NEPA--Environmental Assessment

United
States
Department of
Agriculture
Forest
Service
United
States
Department of
Interior
Bureau of
Land
Management
September
2009
Environmental Assessment
Silverton Landscape Grazing
Analysis
ALLOTMENTS:
Deer Park,
Elk Creek,
Engine Creek/Deer Creek,
Eureka/California Gulch,
Flume,
Gladstone,
Graysill,
Little Molas/West Needles,
Maggie Gulch,
Minnie Gulch,
Needles Mountains,
Picayne/Mineral Point,
Red Mountain, and
West Lime
Columbine Ranger District/Field Office,
San Juan Public Lands
La Plata, Ouray, and San Juan Counties, Colorado
T38-43N, R6-10W, N.M.P.M.
For Information Contact: Rowdy Wood
POB 439
Bayfield, CO, 81122
(970) 884-2512
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, gender, religion,
age, disability, political beliefs, sexual orientation, or marital or family status. (Not all
prohibited bases apply to all programs.) Persons with disabilities who require
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil
Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW,
Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an
equal opportunity provider and employer.

Silverton Landscape Grazing Analysis Environmental Assessment
Table of Contents
Table of Contents........................................................................................................................ ii
List of Tables.............................................................................................................................. iii
List of Figures ............................................................................................................................ iii
Summary...................................................................................................................................... 1
Chapter 1 - Introduction ............................................................................................................. 3
Document Structure.................................................................................................................................. 3
Background............................................................................................................................................... 3
Compliance with Administrative Framework ........................................................................................13
Desired Conditions ................................................................................................................................. 19
Existing Conditions ................................................................................................................................ 20
Purpose and Need for Action.................................................................................................................. 21
Proposed Action ..................................................................................................................................... 25
Decision Framework............................................................................................................................... 25
Public Involvement................................................................................................................................. 25
Issues ...................................................................................................................................................... 26
Chapter 2 - Alternatives............................................................................................................ 28
Alternative 1 – No Action ...................................................................................................................... 28
Design Criteria for Alternatives 2 and 3................................................................................................. 28
Alternative 2 – Current Management ..................................................................................................... 38
Alternative 3 – Adaptive Management/Proposed Action....................................................................... 38
Alternatives Considered but Eliminated from Further Analysis ............................................................ 47
Comparison of Alternatives.................................................................................................................... 50
Chapter 3 - Affected Environment and Environmental Consequences............................... 51
Water Quality ......................................................................................................................................... 52
Vegetation & Soils.................................................................................................................................. 55
Recreation............................................................................................................................................... 63
Wildlife – Threatened and Endangered Species..................................................................................... 68
Wildlife – Sensitive Species ................................................................................................................... 73
Wildlife – Management Indicator Species ............................................................................................. 86
Wildlife – Migratory Birds..................................................................................................................... 92
Socioeconomics...................................................................................................................................... 96
Cultural Resources.................................................................................................................................. 99
Chapter 4 - Consultation and Coordination.......................................................................... 104
Appendix A - Acronyms and Glossary ................................................................................. 105
Appendix B - Citations and References................................................................................ 106
Appendix C - Wildlife Species Lists ...................................................................................... 111
Appendix D – Bighorn Risk Assessment ............................................................................. 120
ii

Silverton Landscape Grazing Analysis Environmental Assessment
List of Tables
Table 2-1. Project Design Criteria for General Management of Permitted Domestic Sheep .......29
Table 2-2. Project Design Criteria to minimize contact between Bighorn and Domestic Sheep ..34
Table 2-3. Current Grazing Management by Allotment...............................................................38
Table 2-4. Potential Adaptive Options – Livestock Grazing Management Actions....................43
Table 2-5. Comparison of Alternatives Based on Significant Issues.............................................50
Table 3-1. Forest-wide habitat and population trends for MIS......................................................88
Table 3-2. Acres of habitat affected for MIS.................................................................................89
Table C-1. Federally Listed Species for the San Juan Public Lands. .........................................111
Table C-2. FS Region 2 and Colorado BLM Sensitive Species. .................................................111
Table C-3. Forest Plan MIS species for the SJNF .......................................................................115
Table C-4. Migratory Bird Species List.......................................................................................117
List of Figures
Figure 1-1. Project Analysis Area................................................................................................. 12
Figure 1-2. Suitable Sheep Grazing Acres.................................................................................... 17
Figure 1-3. Management Emphasis Areas.................................................................................... 18
Figure 1-4. 2008 Data Collection Points....................................................................................... 22
Figure 1-5. Bighorn Overlap......................................................................................................... 23
Figure 1-6. Wilderness Overlap.................................................................................................... 24
Figure 2-1. Proposed Action - Avoidance Areas.......................................................................... 42
Figure 3-1. Proposed Action - Bighorn Overlap........................................................................... 83
iii

SUMMARY
The proposed action analyzed in this Environmental Assessment (EA) constitutes a federal action with
the potential to affect the quality of the human environment on Forest Service (FS) and Bureau of Land
Management (BLM) lands. Therefore, these projects must be analyzed pursuant to the National
Environmental Policy Act (NEPA), which directs federal agencies to carefully consider environmental
concerns in the decision-making process and provide relevant information to the public for review and
comment.
The FS/BLM has prepared this EA in compliance with NEPA and other relevant Federal and state laws
and regulations. This EA discloses potential direct, indirect, and cumulative effects on the human and
biological environment estimated to result from the implementation of the alternatives analyzed.
The Columbine Ranger District/Field Office proposes to continue to authorize livestock grazing on all
or portions of the Silverton Landscape in such a manner that will meet or move resource conditions
toward desired conditions, and be consistent with the Forest Plan and Resource Management Plan
direction, standards and guidelines.
The proposed action is designed to increase the flexibility of livestock grazing systems through
adaptive management, which will allow quicker and more effective response to problems areas when
they are revealed. Problems will be revealed through the use of short- and long-term monitoring.
Application of adaptive management practices should result in healthier soil, watershed, and
vegetative conditions.
The analysis area encompasses approximately 195,050 acres on 8 active sheep allotments, 6 vacant
sheep allotments, and one previously closed allotment. The area is located near Silverton, Colorado, in
San Juan, La Plata, and Ouray Counties, in Townships 38-43 North, Ranges 6-10 West, N.M.P.M. and is
within the Columbine Ranger District/Field Office, San Juan Public Lands, Colorado.
Livestock grazing has been identified in the Forest Plan and Resource Management Plan as an
appropriate use of the public lands and falls under congressional multiple-use mandates (P.L. 86-517,
1960; P.L. 94-579, 1976). This action is needed at this time because in the early 1990’s, the courts
determined that livestock grazing permits should not be re-issued without sufficient National
Environmental Policy Act (NEPA) analysis.
Internal and external scoping has revealed five significant issue topics relating to livestock grazing
on the landscape:
• Soil/Water Impacts
• Vegetation Impacts
• Recreational Experience Impacts
• Wildlife Impacts
• Socio-Economic Impacts
1

These issues led the agency to develop three alternatives:
• Alt. 1 : No Action – No Livestock Grazing (required by law)
• Alt. 2: No Change – Current Management
• Alt. 3: Proposed Action – Adaptive Management
Major conclusions are that while the landscape is general in good condition, most natural resources
benefit from Alternative 3 over Alternative 2, including Water Quality, Vegetation and Soils,
Recreation, Wildlife, and Cultural Resources. Alternative 3 includes design criteria specifically
designed to address issues regarding such things as bighorn sheep, Uncompahgre fritillary butterfly,
and certain areas of recreational conflict. Alternative 1 would be of greatest benefit to natural
resources, but would have negative socio-economic impacts.
Based upon the effects of the alternatives, the responsible official will decide whether livestock
grazing will proceed as proposed, as modified, or not at all; on all or part of the Silverton Landscape;
and if grazing proceeds, will decide what activities, monitoring, and mitigation will be implemented.
2

CHAPTER 1 - INTRODUCTION
Document Structure ______________________________
The FS/BLM has prepared this Environmental Assessment (EA) in compliance with the
requirements found in National Environmental Policy Act (NEPA), agency implementing
regulations, and other relevant Federal and state laws and regulations. This EA discloses the
environmental consequences (direct, indirect, and cumulative environmental impacts) that would
result from the alternatives.
The document is organized into five parts:
Chapter 1-Introduction: The section includes information on the history of the project proposal,
the purpose of and need for the project, and the agencies’ proposal for achieving that purpose
and need. This section also details how the FS/BLM informed the public of the proposal and how
the public responded.
Chapter 2-Comparison of Alternatives: This section provides a more detailed description of the
alternative methods for achieving the stated purpose. These alternatives were developed based on
significant issues raised by the public and other agencies. This discussion also includes possible
design criteria and/or mitigation measures. Finally, this section provides a summary table of the
environmental consequences associated with each alternative.
Chapter 3-Environmental Consequences: This section describes the environmental effects of
implementing the alternatives. This analysis is organized by resource area. Within each section,
the affected environment is described first, followed by the effects of the No Action Alternative
that provides a baseline for evaluation and comparison of the other alternatives that follow.
Chapter 4-Agencies and Persons Consulted: This section provides a list of preparers and
agencies consulted during the development of the EA.
Appendices: The appendices provide more detailed information to support the analyses presented
in the EA.
Additional documentation, including more detailed analyses of project-area resources, may be found
in the project planning record located at the Columbine Ranger District/Field Office in Bayfield,
Colorado.
Background _____________________________________
Project Area Location & Description
The Silverton Landscape is located north of Durango and is within T38-43N, R6-10W, N.M.P.M on
the Columbine Ranger District/Field Office, San Juan Public Lands, La Plata, San Juan, and Ouray
Counties, Colorado. The boundary for this landscape is roughly the same as the boundaries of San
Juan County (see Figure 1-1), with a small portion in La Plata County and minor acreage in Ouray
County. The landscape analysis area includes a total of approximately 195,050 acres, of which
approximately 143,000 acres are FS ownership, and approximately 32,000 acres are BLM
ownership.
The Columbine Ranger District/Field Office falls under the administration of the San Juan Public
Lands Center in Durango, and as such, is managed as a Service First office. Service First is a
partnership strategy to provide better customer service and be more cost effective in the delivery of
that service to users of the public land in southwest Colorado. Both FS and BLM lands are jointly
3

administered with shared facilities, personnel, and management guidance. For this reason, this
analysis encompasses both agencies’ lands within the boundary of the analysis area.
The majority of the project area is located just west and north of the Continental Divide, in
extremely rugged and colorful volcanic mountains, with elevations ranging from approximately
7,700 feet to 14,200 feet. The Animas River has its headwaters in the project area. The project area
is principally alpine tundra, mountain grasslands, and spruce-fir forest. There are smaller areas of
aspen, mixed conifer, ponderosa pine, and mountain shrub communities. Cirques and talus-covered
slopes, along with numerous streams and lakes add diversity to the rugged landscape.
Livestock grazing is just one of many activities that occur on the Silverton landscape. Livestock
grazing has been occurring on many of these allotments since the 1880’s or early 1900’s, and was a
traditional use of the area prior to establishment of the San Juan National Forest in 1905 or the BLM
in 1946. Livestock grazing has been authorized and documented by the FS/BLM since the first half
of the twentieth century, depending on the allotment.
The project area has increasingly become a destination for recreation with over 600,000 visitor days
each year (Virden 1999). Primary recreation activities include sightseeing and motorized recreation
along the Alpine Loop Backcountry Byway, hiking and backpacking, viewing wildlife, fishing,
whitewater boating, touring historic sites, snowmobiling, and backcountry skiing. BLM permits a
developed expert ski area, Silverton Mountain, in the project area. There are two developed Forest
Service campgrounds and several day-use areas in the landscape. Both the Continental Divide Trail
and the Colorado Trail pass through the landscape. A large portion of the landscape is included in the
Weminuche Wilderness.
The Silverton area is well-know for its rich historical heritage. The early settlement of the Silverton
area is closely linked with the discovery of gold and the subsequent boom-bust cycles of the mining
industry. The area's mining history follows the general pattern of mining development in the San
Juan Mountains. Exploration began in the early 1860s, soon after the discovery of gold in Colorado.
Silverton became established as one of the early mining centers of the region (USDI 2004). Limited
mining continued at one site until about 1994, but currently there is little or no active mining. Today,
the area is known for its abundance of historical structures, mining routes, and other mining artifacts.
Allotment Summaries
Descriptions of each allotment in this landscape follow, including summaries of past grazing use, in
order to put the proposed action in context with the intensity of historical use of the landscape for
grazing.
Deer Park Allotment
This allotment is located directly southeast of Silverton, Colorado. Elevations vary from around
9,500 feet to just over 13,400 feet. The northern half of the allotment, containing about 5,300 acres
is administered by the Bureau of Land Management, and the southern half, containing about 7,300
acres is administered by the Forest Service and is within the Weminuche Wilderness. About 800
acres of private land is within the allotment, for a total of about 13,400 acres on the Deer Park
Allotment. The terrain consists of high ridges and steep slopes with canyons throughout rugged
mountains and some rolling to flat alpine meadows. The cover type on the allotment consists of
some subalpine vegetation with Engelmann Spruce and subalpine fir plant communities, mountain
meadows, and mostly alpine meadows dominated by numerous grasses and forbs.
Recreational use of this allotment is significant due to most of it being within the Weminuche
Wilderness and having the Continental Divide Trail bordering the entire east boundary of the
4

allotment. The approximately 800 acres of private land within the allotment consists mostly of
mining claims.
Grazing in this area began in 1915. The earliest records available date back to 1929. The present
Deer Park Allotment was is now made up of the former Cunningham Gulch and Deer Park
Allotments. Records are unclear when Cunningham Gulch was absorbed into Deer Park. From
1929 to 1934, the number of sheep that grazed Cunningham Gulch fluctuated between 400 and 720
head. The grazing season was July 1 st through September 20 th . In 1935, 500 sheep were permitted
to graze the allotment. From 1945 to 1948, 1,000 head grazed the Cunningham Gulch. In 1951 the
season was shortened and began in mid-July. The stocking rate decreased to 800 head in 1953. By
1959 the permits began to distinguish between BLM and Forest Service land use. There were no
records of the BLM grazing permits. One thousand head began to graze Cunningham in 1969, and
by 1975 the permit actions were addressed to Deer Park (National Forest) and Cunningham Gulch
(BLM) allotments. In 1984, the operating instructions were only made up for Deer Park while still
including the BLM permitted sheep. During the mid 1980’s, 900 to 1,100 sheep grazed Deer Park
from mid-July until mid-September. From 1887 to the present, 1,000 sheep have been permitted to
graze Deer Park Allotment. The permitted sheep access the Deer Park allotment by being trucked to
and from the corrals in Cunningham Gulch and then trailing from those onto the allotment.
Elk Creek Allotment
This allotment is located approximately 5 miles east of Silverton, Colorado. Elevations vary from
10,000 feet to 13,600 feet. This allotment contains approximately 6,550 acres; 350 are private. The
northern half of the allotment, 1,200 acres, is administered by the Bureau of Land Management, the
southern half, 5,000 acres, is administered by the Forest Service and is within the Weminuche
Wilderness. The terrain consists of high ridges and steep slopes with canyons throughout rugged
mountains. The cover type on the allotment consists of some subalpine vegetation with Engelmann
spruce and subalpine fir plant communities, mountain meadows, and mostly alpine meadows
dominated by numerous grasses and forbs.
There are 350 acres of private mining claims on both the Forest Service and BLM portions of the
allotment. These claims are not fenced, so they are grazed. Recreational use of this allotment is
significant due to most of it being within the Weminuche Wilderness and having the Continental
Divide Trail bordering the entire west boundary of the allotment.
Grazing in this area began in 1915. The earliest records available of grazing date back to 1949. Elk
Creek Allotment was formally divided into two allotments, North Elk Creek and South Elk Creek
Allotments. From July 11 th to September 15 th , 600 head of sheep grazed South Elk Creek from July
1 st to September 15 th . In 1950, the numbers increased to 900 head. Records of grazing North Elk
became available in 1953, when 1000 head grazed each of the north and south allotments of Elk
Creek, and the season on South Elk Creek was reduced from Mid-August to mid-September. In
1959, the numbers of North Elk Creek were reduced to 900, and in 1968, South Elk Creek was also
reduced to 900 head. In 1969, the allotments combined to form Elk Creek Allotment as it is today.
From July 11 th to September 15 th , 1000 head grazed Elk Creek. In 1985, the Forest Service
permitted 785 sheep and the BLM permitted 215 head to graze the allotment. In 1994, the Stoney
Allotment of the Rio Grande National Forest (Creede Ranger District) was incorporated into the
grazing rotation. Currently, 1000 sheep are permitted to graze the Elk/Stoney Allotment (785 FS
and 215 BLM). The permitted sheep access the Elk Creek allotment by being trucked to and from
the corrals in Cunningham Gulch and then trailing from those onto the allotment.
5

Engine Creek/Deer Creek Allotment
This Engine Creek portion of this allotment is located in the southwest portion of the analysis area.
The Engine Creek Allotment is 30 miles north of Durango, Colorado. Elevations vary from 9,400
feet to 12,600 feet. This allotment contained about 7,400 acres. A small portion of 10 acres is
private land. The terrain consists of high ridges and steep slopes with canyons throughout rugged
mountains and some rolling to flat alpine meadows. The cover type on the allotment consists of
some subalpine vegetation with Engelmann Spruce and subalpine fir plant communities, mountain
meadows, and alpine meadows dominated by numerous grasses and forbs.
This area is popular for recreational use, having three system trails, including the Colorado Trail.
Grazing in this area began in the early 1900’s. The earliest records available of grazing begin in
1928. From 1988 to 1935, 1,200 head of sheep grazed Engine Creek from June 16 th to September
20 th . From 1945 to 1955, 750 head of sheep grazed Engine Creek and the season was shortened to
July 1 st through September 20 th . In 1959, the numbers were increased to 925 head. Between 1964
and 1974, the numbers fluctuated between 800 head and 1,150 head of sheep. The adjacent
allotment to the west, Flume Allotment, was incorporated into the rotation in 1975; where 1,150
head grazed the two allotments. Engine Creek was rested in 1983 and then grazed without Flume by
a band of 800 to 1,150 sheep through 1992. In 1995, the adjacent allotment to the east, Deer Creek
Allotment was included into the grazing rotation. The most recent years of nonuse have been 1999,
2006, 2007, and 2008.
The Deer Creek portion of this allotment is located in the southwest portion of the analysis area.
The Deer Creek Allotment is 30 miles north of Durango, Colorado. Elevations vary from 9,400 feet
to 12,600 feet. This allotment contained about 9,500 acres. Only about 5,000 of these acres are
suitable for grazing. The terrain consists of high ridges and steep slopes with canyons throughout
the rugged mountains and some rolling to flat alpine meadows. The cover type on the allotment
consists of some subalpine vegetation with Engelmann Spruce and subalpine fir plant communities,
mountain meadows, and alpine meadows dominated by numerous grasses and forbs.
This area is popular for recreational use, having three system trails, including the Colorado Trail.
Highway 550 bisects Deer Creek Allotment and is a National Scenic byway attracting more
recreational users.
Grazing in this area began in the early 1900’s. The earliest records available of grazing in this area
began in 1949. Prior to 1971, Deer Creek was divided into Lime Creek and Deer Creek S&G
Allotments. From July 1 st to September 20 th , two bands of 800 sheep grazed the two allotments.
After combining the allotments into Deer Creek/Lime Creek Allotment in 1971, one band of 900 to
1,150 sheep grazed the allotment every season. The operating instructions starting in 1980 permitted
1,150 sheep to graze the Deer Creek allotment. One band of 1,150 sheep was permitted to graze
Deer Creek until 1987. The numbers were reduced to 800 in 1988, and in 1989, 850 sheep were
permitted to graze Deer Creek. In 1995, Engine Creek Allotment to the west was included in the
grazing rotation. Since this time, one band of 850 sheep has grazed the two allotments. Deer Creek
and Engine Creek have both been in nonuse in 1999 and in 2006-2008.
The Engine Creek and Deer Creek Allotments were administratively combined in 2009 into one
allotment, which is currently permitted for 1000 sheep, and was active in 2009. The permitted sheep
access the Engine Creek/Deer Creek allotment by being trucked to and from the Lime Creek corrals
along the Lime Creek road and then trailing from those onto the allotment.
6

Eureka/California Gulch Allotment
This allotment is located 6 miles northeast of Silverton, Colorado. Eureka Allotment is administered
by the Bureau of Land Management. Elevations on the allotment vary from 9,800 feet to just over
13,400 feet. This allotment contains about 9,300 acres, with about 3,000 acres of private land
consist of mining claims. The terrain consists of high ridges and steep slopes with canyons
throughout rugged mountains. The allotment occurs at the headwaters of the West Fork and the
South Fork of the Animas River. The cover type on the allotment consists of subalpine vegetation
with Engelmann Spruce and subalpine fir plant communities, mountain meadows, and alpine
meadows dominated by numerous grasses and forbs.
The records available do not provide historical use of this allotment. According to Actual Use
Forms that start in 1971, two bands of 1500 sheep each would graze 2 of the 3 pastures of Eureka
Allotment, and rest one every year. The 1982, the records described a 3 pasture deferred rotation to
be grazed by two bands of sheep. In 1992, only one band of sheep began to graze the allotment.
Currently, one band of 1275 sheep graze the Eureka Allotment. The permitted sheep access the
Eureka/California Gulch allotment either by being trucked to and from the corrals at Eureka and then
trailing from those onto the allotment or by utilizing the Ridge Stock Driveway on the Gunnison,
Grand Mesa and Uncompahgre National Forest and Gunnison Field Office.
Flume Allotment
This allotment is located on the northwest portion of the analysis area about 30 miles north of
Durango, Colorado. Elevations vary from 8,000 to 13,700 feet. This allotment contains about
11,800 acres; about 200 acres are private. The terrain consists of high ridges and steep slopes with
canyons throughout the rugged mountains. The cover type on the allotment consists of mixed timber
containing Engelmann spruce, subalpine fir, and aspen, mountain meadows, and alpine meadows
dominated by numerous grasses and forbs.
The Flume allotment has been used for sheep grazing since the settlement of the Animas River
Valley in the 1880’s. Records date back to 1916. During this time, the Cascade Creek drainage was
the Cascade Allotment. From 1916 to 1928, it stocked 1,500 head of sheep from June 16 th through
October 15 th . Then the stocking rate decreased to 1,200 head until 1935, and the sheep grazed until
September 15 th . The next available records start in 1945. Flume Allotment stocked 800 head from
July 1 st to September 20 th , and Cascade Allotment stocked 1,055 head. From 1948 to 1953 the
number decreased to 750 head in both allotments. 1955 was the last year Cascade was stocked with
sheep until it became part of Flume and Engine Creek Allotments. Cascade stocked 925 sheep on
both sides of the Cascade Creek drainage for the full season; this year Flume stocked 750 head. In
1956, the numbers on Flume were increased to 925 until 1964. For the next two years, 800 head
grazed the allotment and then the band number increased to 925 again. In 1969, 900 to 1,000 head
grazed Flume until it was included in the rotation of the adjacent allotment to the east, Engine Creek,
in 1975. Flume and Engine Creek were grazed by one band of 1,150 sheep until 1983. Flume was
last grazed in 1983 without Engine Creek in the rotation. The permit was waived back to the United
States in 1989. The allotment has been vacant since.
The most recent permittee had difficulty grazing Flume due to high predator losses and lack of
controlling the sheep bands due to very steep terrain. A tree seedling plantation was established in
the mid 1980’s, the nonuse and resting of Flume was advantageous to the establishment of this
plantation. During the Missionary Ridge Fire of 2002, a band permitted on a Missionary Ridge
allotment grazed this area. The permitted sheep access the Flume allotment by trailing along US
Hwy 550.
7

Gladstone Allotment
This allotment is administered by the Bureau of Land Management. It is located directly north of
Silverton, Colorado. Gladstone Allotment occurs at the head waters of Cement Creek. Elevations
on the allotment vary from 9,400 feet to just over 13,400 feet. This allotment contains about 12,000
acres, of which about 4,300 acres are private land consists mainly of mining claims. The terrain
consists of high ridges and steep slopes with canyons throughout rugged mountains. The cover type
on the allotment consists of subalpine vegetation with Engelmann spruce and subalpine fir plant
communities, mountain meadows, and alpine meadows dominated by numerous grasses and forbs.
In the past, a lot of mining activity occurred on the private land within this allotment. This also a
popular area for summer recreation and winter sports.
The records available do not provide historical use of this allotment. According to Actual Use
Forms that start in 1969, this allotment was grazed by one band of 884 to 1,000 sheep through 1996.
Records are missing from 1997 to 2002. Starting in at least 2003, 700 yearling ewes have been
permitted to graze Gladstone Allotment. In 1993, the current Gladstone Allotment boundary was
created to include Cement Creek that was formally part of the U.S. Basin Allotment. This boundary
adjustment allowed for more evenly distribution of grazing between the two allotments by two bands
of sheep. Currently, one band of 924 ewes with lambs are permitted on the Gladstone Allotment.
This often stocked with yearling ewes without lambs. The permitted sheep access the Gladstone
allotment by being trucked to Hancock Gulch and from corrals near the top of Red Mountain Pass.
Graysill Allotment
This allotment is located on the northwest portion of the analysis area about 30 miles north of
Durango, Colorado. Elevations vary from 10,260 to 12,500 feet. This allotment contains about
2,400 acres all on National Forest land. The cover type on the allotment consists of grassy mountain
meadows, mixed timber containing Engelmann spruce, subalpine fir, white fir, aspen, and alpine
meadows dominated by numerous grasses and forbs.
The Graysill Allotment has been used for sheep grazing since the settlement of the Animas River
Valley in the 1880’s. It had been grazed heavily and managed poorly during its early use. Records
only date back to 1940. Historically, Graysill and Corral Draw Allotments (now part of Upper
Hermosa Allotment) allotments were grazed conjointly until Corral Draw began stocking cattle.
Stocking rates of 1,800 head of sheep grazed Graysill and Corral Draw in 1940. During 1941
through 1943, grazing seasons the numbers were reduced to 1,400 head. The numbers were reduced
to 900 sheep in 1944 and 1945. During the 1946 and 1947 seasons, 800 head were permitted on the
allotments. The numbers decreased again to 750 head in 1948 through 1958. In 1959, the numbers
were increased to 900 head until the allotment became vacant. The grazing season for the Graysill
Allotment was from July 1 st through September 20 th . Graysill has been vacant since 1966. The
permitted sheep access the Graysill allotment by trailing along US Hwy 550.
Little Molas/West Needles Allotment
This allotment is located directly south of Silverton, Colorado. Elevations vary from 8,275 to
13,400 feet. This allotment contains about 2,500 acres of land administered by the Bureau of Land
Management, and 19,871 acres are managed by the Forest Service; 12,201 acres are within the
Weminuche Wilderness. Another approximately 800 acres of the allotment is private land. The
terrain consists from rolling hills to high ridges and steep slopes with canyons throughout the rugged
mountains. The cover type on the allotment consists of mixed timber containing Engelmann spruce,
subalpine fir, and aspen, mountain meadows, and alpine meadows dominated by numerous grasses
and forbs.
8

There is considerable recreational usage of the allotment due to the Colorado Trail and the Crater
Lake Trail bisecting the allotment. the Durango-Silverton narrow gauge train tracks run along the
Animas River on the eastern boundary of the allotment.
The Molas Lake Allotment stocked 1000 head of sheep from 1949 to 1972. In 1973, the records
indicated that the area around Big Molas Lake was administered by the BLM. At this point, 200
head grazed the Big Molas Allotment and 800 head grazed the Little Molas Allotment. In 1987, the
two allotments were combined and one band of 1000 sheep was permitted to graze the allotment.
One band of 900 sheep grazed the West Needles from 1954 until 1992. In 1993, Little Molas and
West Needles were grazed by one band of 1000 head of sheep. Then in 1994, an Environmental
Assessment combined the Little Molas and West Needles Allotments. This better facilitated sheep
management and utilization of the available resources. The last record of grazing was in 1999.
During the Missionary Ridge Fire of 2002, a band permitted on a Missionary Ridge allotment grazed
this area. The permitted sheep access the Little Molas/West Needles allotment by being trucked to
and from corrals near Big Molas Lake.
Maggie Gulch Allotment
This allotment is administered by the Bureau of Land Management. It is located 6 miles northeast of
Silverton, Colorado. Elevations on the allotment vary from 9,720 feet to just over 13,200 feet. This
allotment contains approximately 6,600 acres, 3,350 acres of those are private consisting of mining
claims. The terrain consists of high ridges and steep slopes with canyons throughout rugged
mountains. The cover type on the allotment consists of subalpine vegetation with Engelmann spruce
and subalpine fir plant communities, mountain meadows, and alpine meadows dominated by
numerous grasses and forbs.
In the past, a lot of mining activity occurred on the private land within the allotment. Approximately
27% of the suitable consists of mining claims. The mining claims are not fenced and have been
grazed in the past. There have been no conflicts with mining and grazing. Maggie Gulch is also a
popular area for summer recreation and winter sports.
The records available do not provide historical use of this allotment. The earliest records available
of grazing date back to 1953. The Forest service permitted 670 of the 1,000 sheep to graze the
allotment until 1976 (the other 330 sheep were permitted by the BLM). The grazing season was
from July 11 th to September 15 th . A Multiple Use Survey Report of 1970 described five pasture
grazing rotation system. Currently this allotment is permitted in conjunction with the West Pole
allotment administered by the Rio Grande National Forest, for 1000 ewes. The permitted sheep
access the Maggie allotment by being trucked to and from the Eureka corrals.
Minnie Gulch Allotment
This allotment is located 8 miles northeast of Silverton, Colorado. Minnie Gulch Allotment is
administered by the Bureau of Land Management. Elevations on the allotment vary from 9,600 feet
to just over 13,000 feet. This allotment contains about 3,000 acres, including 400 acres of private
land consisting mainly of mining claims. The terrain consists of high ridges and steep slopes with
canyons throughout rugged mountains. The cover type on the allotment consists of subalpine
vegetation with Engelmann Spruce and subalpine fir plant communities, mountain meadows, and
alpine meadows dominated by numerous grasses and forbs.
In the past a lot of mining activity occurred on the private land within the allotment. Minnie Gulch
is also a popular area for summer recreation and winter sports.
The records available do not provide historical use of this allotment. The earliest records available
of grazing date back to 1953. From July 1 st to September 15 th , 800 head of sheep grazed Minnie
9

Gulch. In 1956, the numbers decreased to 600 head that grazed July 10 th thru September 5 th . In
1971, a band of 700 sheep grazed until the last record of grazing in 1983 from July 20 th through
early September. Permitted sheep could access the Minnie allotment by being trucked to and from
the Eureka corrals or trailed using the Ridge Stock Driveway on the Gunnison, Grand Mesa and
Uncompahgre National Forest and Gunnison Field Office.
Needles Mountains Allotment
This allotment is located about 25 miles northeast of Durango, Colorado, on Forest Service lands.
Elevations on the allotment range from about 7,500 feet to over 14,000 feet. The allotment contains
approximately 46,000 acres. An extremely limited amount of the allotment is considered suitable for
grazing due to rugged topography. The allotment is completely within the Weminuche Wilderness,
with the exception of the Animas River corridor, along which the Durango-Silverton narrow gauge
train tracks run. There is a tremendous amount of recreational use within this part of the wilderness.
There are no known records of any permitted livestock grazing ever occurring on the Needles
Mountain Allotment.
Picayne/Mineral Point Allotment
This allotment is located on the northern most portion of the analysis area about 9 miles northeast of
Silverton, Colorado. Picayne/Mineral Point Allotment is administered by the Bureau of Land
Management. Elevations on the allotment vary from 10,200 feet to just over 13,000 feet. This
allotment contains about 5,500 acres; 2,100 of those are private consisting mainly of mining claims.
The terrain consists of high ridges and steep slopes with canyons throughout high mountains. The
cover type on the allotment consists mostly of alpine meadows.
The current Picayne/Mineral Pt. Allotment was originally separated into two allotments, Picayne
S&G and Mineral Pt. In 1990, the current Picayne/Mineral Point allotment boundary was created.
The BLM records do not provide historical use of this allotment. The earliest recorded grazing dates
back to 1967. The only available records are Actual Use Forms. Seven hundred to 1,027 sheep have
grazed the Picayne Gulch area until the current allotment boundary was created. Since 1990, one
band of 1031 sheep has grazed the allotment from July 7 th to September 19 th , splitting the period of
use between the Mineral Point (north) and Picayne (south) units of the allotment. The permitted
sheep access the Picayne/Mineral Point allotment by using the Ridge Stock Driveway on the
Gunnison, Grand Mesa and Uncompahgre National Forest and Gunnison Field Office.
Red Mountain Allotment
This allotment is located directly northwest of Silverton, Colorado. Elevations vary from 9,400 feet
to just over 13,400 feet. This allotment contains about 12,600 acres; about 2,000 acres are on private
land and consist mainly of mining claims. The terrain consists of high ridges and steep slopes with
canyons throughout rugged mountains. The cover type on the allotment consists of subalpine
vegetation with Engelmann spruce and subalpine fir plant communities, mountain meadows, and
alpine meadows dominated by numerous grasses and forbs.
This allotment was formally made up of the U.S. Basin and Mill Creek Allotments. In 1994, the two
allotments were combined and the current Red Mountain allotment boundary was created.
The earliest records available of grazing date back to 1953. From July 3 rd to September 13 th , 700
head of sheep grazed U.S. Basin, and 800 head grazed Mill Creek. From 1995 to 1961, 750 grazed
Mill Creek. Until 1989, the numbers increased to 850 head and then 900 head in Mill Creek. From
1989 until 1994, 1,025 head grazed Mill Creek from August 16 th to September 6 th . In 1984, one
band of 927 head grazed the U.S Basin allotment. In the early 1990’s, 850 sheep were permitted to
10

graze U.S. Basin. Since the current boundary was created in 1994, one band of 1,000 head of sheep
has been permitted to graze the Red Mountain S&G allotment from July 1 st to September 15 th . The
permitted sheep access the Red Mountain allotment by being trucked to the Ophir Pass road and
from corrals near the top of Red Mountain Pass.
West Lime Allotment
This allotment is located west of Silverton, Colorado. Elevations vary from 8,275 to 13,400 feet.
This allotment contains about 20,000 acres of national forest and 800 acres of private land. The
terrain consists from rolling hills to high ridges and steep slopes with canyons throughout rugged
mountains. The cover type on the allotment consists of mixed timber containing Engelmann spruce,
subalpine fir, and aspen, mountain meadows, and alpine meadows dominated by numerous grasses
and forbs.
There is considerable recreational usage of the allotment due to the Rico/Silverton-Colorado Trail
and the Ice Lake Trail that is within the allotment. The South Mineral campground is also a popular
recreation site. The 800 acres of private land consists mostly of mining claims.
The current West Lime Allotment includes the historic allotments of Ice Lake, Bandora, and West
Lime. From 1953 to 1960, both Ice Lake and Bandora stocked 700 head of sheep. The two
allotments were combined in 1961, and 800 sheep grazed the allotment. In 1960, the number
increased to 860 head. In 1954, the West Lime allotment stocked 800 head of sheep. This number
increased to 860 in 1963. The three allotments were grazed by 2 bands of 860 sheep in a restrotation
grazing system, this first year, West Lime was rested. This rotation system lasted only a
couple years, in 1971, the numbers increased to 1000 head (860 sheep were permitted to graze West
Lime and 140 sheep were permitted to graze Bandora-Ice Lake.) In 1976, another rest-rotation
grazing system was implemented, this time including the Whitehead Unit of Deer Park allotment and
Cunningham Gulch allotment. For the first year of this rotation, West Lime was rested and 3 bands
of 860 sheep grazed the three other allotments. This rotation system continued with the same
stocking rate until 1983. In 1984, both West Lime and Bandora-Ice Lake ran 860 sheep. In 1987,
the number increased to 1000 and the same band also grazed Bandora-Ice Lake. In 1989, 2 bands of
860 sheep grazed West Lime and Bandora-Ice Lake. 1994 was the last year Bandora-Ice Lake was
stocked. In 1991, 960 sheep grazed West Lime until 1999, when it was last stocked. The records
are unclear as to when the two allotments were combined. The permitted sheep accessed the West
Lime allotment through the South Mineral drainage or from the corrals at Big Molas Lake or Lime
Creek.
11

Figure 1-1. Project Analysis Area
12

Compliance with Administrative Framework __________
Forest Land and Resource Management Plan
Livestock grazing has been determined by the San Juan National Forest Amended Land and
Resource Management Plan (1992), hereafter referred to as the Forest Plan, as an appropriate use of
the Forest and falls under the multiple-use mandate of the Forest Service (P.L. 86-517, 1960). Forest
Plan-level analysis for grazing has determined that approximately 40,400 acres (28%) of the total
FS acres within the project area are generally suitable for grazing (Figure 1-2). This determination is
based on factors including ownership, topography, slope, vegetation type, and distance to water. This
is a rough estimation of the amount of land that is suitable for grazing, and may be further refined at
the project level.
Forest Plans establish programmatic direction for the management of National Forest System lands.
The current Forest Plan management alternatives and their environmental consequences were
analyzed in an environmental impact statement (EIS). The selection of an alternative and the
rationale for the decision are documented in the Record of Decision.
Specifically, a Forest Plan does the following:
• Establishes Forest-wide goals, objectives, and management direction;
• Establishes management areas and associated direction;
• Identifies lands generally suitable for a variety of uses;
• Recommends areas suitable for wilderness and other special designations and provides nonwilderness
allocations;
• Establishes monitoring and evaluation requirements.
The direction for rangeland management includes goals, objectives, standards, guidelines, and the
identification of lands generally suitable for livestock grazing. The following critical forest-wide
General Direction statements relate to range management and livestock grazing (pp. III- 30-34, 46,
47, 72):
• Provide forage to sustain local dependent livestock industry as well as wildlife populations
agreed to in Statewide Comprehensive Wildlife Management Plans for the National Forest
System lands.
• Manage livestock and wild herbivores forage use by implementing allowable use guides,
which are specified by type of livestock grazing system.
• Achieve or maintain satisfactory range conditions on all rangelands.
• Treat noxious weeds.
• Manage riparian areas to reach the latest seral stage possible within the stated objectives.
• Improve or maintain water quality to meet State water quality standards.
• Maintain soil productivity, minimize man-caused erosion, and maintain the integrity of the
associated ecosystem.
13

Specific Management Emphasis Areas (Figure 1-3) also have Direction, Standards, and Guidelines
associated with them.
• 1B: Emphasis is on winter sports areas (III-93)
o Manage livestock grazing to enhance recreation opportunities in existing and proposed recreation sites.
(III-94)
o Utilize low investment management systems such as season-long or deferred grazing, unless improved
management systems are warranted in conjunction with management of adjacent areas. (III-95)
• 2A: Emphasis is on semi-primitive motorized recreation opportunities (III-105)
o Manage livestock distribution and stocking rates to be compatible with recreation use. Locate
structural improvements to meet visual quality objectives. (III_109)
o Utilize extensive management systems such as season-long or deferred grazing. (III-109)
o Protect regeneration from livestock damage in areas managed for timber production. (III-110)
o Construct and maintain [structural improvements] necessary to implement management systems. Use
on-site or rustic materials and mechanical methods compatible with prescription objectives. (III-110)
• 2B: Emphasis is on rural and roaded-natural recreation opportunities (III-118)
o Manage livestock distribution and stocking rates to be compatible with recreation use. Locate
structural improvements to meet visual quality objectives. (III-122)
o Utilize extensive management systems such as season-long or deferred grazing. (III-122)
o Protect regeneration from livestock damage. (III-122)
o Construct and maintain [structural improvements] necessary to implement management systems. Use
on-site or rustic materials and mechanical methods compatible with prescription objectives. (III-123)
• 3A: Emphasis is on semi-primitive non-motorized recreation in roaded or non-roaded areas (III-130)
o Manage livestock distribution and stocking rates to be compatible with recreation use. Locate
structural improvements to meet visual quality objectives. (III-133)
o Utilize extensive management systems such as season-long or deferred grazing. (III-133)
o Construct and maintain allotment boundary fences, short drift fences and water developments
necessary to implement management systems. Use on-site or rustic materials and mechanical methods
compatible with prescription objectives. (III-134)
• 6B: Emphasis is on livestock grazing (III-179)
o Use only intensive grazing systems or remove livestock when recovery of range condition cannot be
accomplished by an intensive grazing system. (III-187)
o Improve range condition to fair or better or forage value rating to moderately high or better. (III-187)
• 7E: Emphasis is on wood-fiber production and utilization (III-209)
o Utilize improved management systems such as rest-rotation, deferred rotation, rotation, or alternate
years. (III-216)
o Utilize transitory forage that is available where demand exists and where investments in regeneration
can be protected. (III-216)
o Protect regeneration from livestock damage. (III-216)
• 1.11-1.13: Emphasis is on wilderness values. (FP Amendment #20)
o Livestock grazing activities shall be permitted in accordance with congressional guidelines.
FSM2320.5 (II-26 in Amendment 20)
This Plan guidance is used as the foundation to compare the current conditions of allotments to the
desired conditions for the allotments. The desired condition is then further defined at the project
level (p.19). An examination of whether each applicable Forest Plan direction item is being met can
be found in the project record. A brief summary of that examination reveals that Forest Plan
direction, standards and guidelines for grazing are generally being met, with the exception of
reducing the total acreage of noxious weeds, and the reasons for not meeting this direction are not
attributed to grazing.
Resource Management Plan
Livestock grazing has been determined by the San Juan/San Miguel Resource Management Plan
(1985), hereafter referred to as the RMP, to be an appropriate use of the project area based in part on
the RMP’s suitability determinations. RMP-level analysis for grazing has determined that
14

approximately 9,030 acres (28%) of the total BLM acres within project area are generally suitable
for grazing (Figure 1-2).
Resource Management Plans establish programmatic direction for the management of BLM lands.
General Grazing Objectives in the RMP state: “Maintaining or improving the vegetation component
of the ecosystem is key to enhancing the resource values of the planning area to permit a balanced
mix of uses to ensure sustained yield. (p.5)”
BLM policy directs the BLM to focus available funding and resources on those areas where
problems and conflicts exist. The RMP places grazing allotments in one of three categories: “I”,
Improve; “M”, Maintain; or “C”, Custodial. The allotments in this landscape are all considered “M”
class - Maintain current satisfactory conditions - and will accordingly, receive attention as a second
priority (RMP p.6).
The RMP designates the BLM areas within the project boundary as emphasis areas:
• A - Livestock Management – “Manage suitable vegetation types for increased, sustained livestock production. One
goal is to improve range condition and productivity on native rangelands. Use improved management systems such
as rest-rotation and deferred-rotation if appropriate…Develop AMP’s on 71 priority allotments. (p.27)”
• C - Recreation – “Manage livestock under reduced intensity to utilize available forage and maintain plant vigor
while not degrading recreation values…Manage livestock grazing to make it compatible with recreation use.
(p.35)”
• Kw - Municipal Watershed – “Manage suitable vegetation types under low to moderate intensity for livestock
production with the intent to use available forage and maintain plant vigor. Reduce the number and/or season of use
for livestock where needed to achieve soil and water program objectives. (p.55)” This Management Area is found
within the project area boundary, but not within an active allotment.
These are used as the foundation to compare the current conditions of allotments to the desired
conditions for the allotments. The desired condition is then further defined at the project level (p.19).
An examination of whether each applicable RMP direction item is being met can be found in the
project record. A brief summary of that examination reveals that RMP direction is being met, or
conditions are moving towards the described direction.
Allotment Management Plans (AMP’s) and NEPA Analysis
While the Forest Plan/RMP establishes the general suitability of an area for livestock grazing, the
decision to authorize livestock grazing on a particular area of land is the outcome of a
comprehensive, integrated resource analysis for the particular allotment(s). This analysis, conducted
according to NEPA, is required in order to authorize livestock grazing on the project area, to
prescribe site-specific management of the rangeland resources, and to ensure management is capable
of meeting or moving toward desired conditions. Analysis and associated decisions made at this
level are documented in an EA (such as this document) or an EIS and a decision document, and
implemented through the permit, AMP, and annual operating instructions.
15

Livestock Grazing Permits
Livestock grazing permits authorize a permittee to graze livestock on National Forest System Lands
or BLM lands, and are issued for a ten-year period on specific portions of the project area.
The permittee is required by the permit to graze under specified terms and conditions designed for
resource protection and enhancement, as described in the AMP, which is incorporated as part of the
permit. Permits are administered annually through issuance of Annual Operating Instructions
(AOI’s), which can vary from year to year. Livestock grazing permits by themselves do not authorize
the permit holder to develop water, construct fences, build roads or trails, manipulate vegetation, or do
other ground disturbing activities. Grazing permits may require the permittee to maintain assigned
rangeland improvements.
16

Figure 1-2. Suitable Sheep Grazing Acres
17

Figure 1-3. Management Emphasis Areas
18

Desired Conditions _______________________________
The need for a change in management is identified by comparing specific descriptions of what is
desired across the landscape (desired conditions) to what currently exists on the landscape in the
analysis area (existing conditions). The FS analysis team defined project-specific desired conditions
for this landscape. If project-specific desired conditions are being met, then Forest Plan/RMP
Direction will also be met. Desired conditions are defined, and existing conditions are measured
under the following methodologies:
Methodology: The Proper Functioning Condition (PFC) methodology was chosen for primary
monitoring of riparian areas (Prichard 1998). The PFC ratings qualitatively evaluate riparian
condition based in part on presence/absence and abundance of specific vegetation and the
interactions of that vegetation with geology, hydrology, and soils. If unsatisfactory ratings indicate
the need for more intensive monitoring, other quantitative methods would also be used.
Two different upland vegetation methodologies were chosen in order to follow appropriate nationwide
agency direction for each agency. Both methodologies are qualitative assessments for
rangeland conditions which consider similar factors such as vegetative and soil conditions. Upland
vegetation communities were measured using the Rangeland Health Matrix (RHM) methodology on
Forest Service lands, and the Standards for Public Land Health Assessment (LHA) method on BLM
lands.
These methods are described further under Monitoring for Alternative 3 (p.44).
Desired Conditions for Riparian Areas: Riparian areas are functioning properly as indicated by a
rating of “Proper Functioning Condition.” Attaining a PFC rating provides a stable foundation and a
physically functioning riparian area that can withstand low to moderate flood events.
Desired Conditions for Upland Areas on Forest Service lands: Upland areas are in a healthy
condition, as indicated by an RHM rating of “healthy” or “at risk with an upward trend” (moving
towards meeting), and lands which are currently “healthy” must maintain that rating.
Desired Conditions for BLM lands: BLM lands are in a healthy condition, as indicated by a LHA
rating of “meeting the standard” or “not meeting the standard, but making significant progress
towards meeting the standard” for all five Colorado Standards for Public Land Health:
Standard 1 relates to uplands soils,
Standard 2 relates to riparian systems,
Standard 3 relates to plant and animal communities,
Standard 4 relates to special status, threatened and endangered species,
Standard 5 relates to water quality;
Lands which are currently “meeting the standard” must maintain that rating. Additionally, the LHA
should indicate that upland areas “Conform with Guidelines for Livestock Grazing Management.”
19

Desired Conditions for Bighorn: Reduce or eliminate the likelihood of contact between wild sheep
and domestic sheep and goats. Manage domestic sheep grazing practices to reduce potential for
geographical and/or temporal overlap between domestic sheep and bighorn sheep in active domestic
sheep allotments. In areas of mapped overlap and/or close proximity of domestic sheep and bighorn
sheep summer ranges, apply design criteria to reduce or eliminate potential for contact between
domestic sheep and wild sheep. Manage domestic sheep to achieve more effective separation from
wild sheep.
Desired Conditions for Wilderness: “Natural succession occurs on all existing vegetative
communities, and is influenced by natural processes and disturbance. The structure, composition,
function and spatial distribution of vegetative types are the result of natural-successional processes.
Human influence on vegetation is unnoticeable. Plant species are indigenous to the immediate area,
with exotic plants being extremely rare. Non-indigenous species composition does not increase from
an established baseline….A range of habitats is sustained for all naturally occurring species.
Sensitive species do not move toward Threatened and Endangered listing. … Human influence on
physical features such as soils and geologic materials is unnoticeable (SJNF 1998).”
Existing Conditions ______________________________
The need for a change in management is identified by comparing specific descriptions of what is
desired across the landscape (desired conditions) to what currently exists on the landscape in the
analysis area (existing conditions).
In 2008, the FS/BLM collected data to document existing conditions using the above-described
methodologies.
Existing Conditions for Riparian and Upland Vegetation: A map of the 2008 riparian and upland
vegetation existing conditions is found in Figure 1-4. Of a total of 28 data points (includes PFC,
RHM, and LHA), 27 (96%) were meeting desired conditions.
In addition to qualitative data collected in 2008, the FS/BLM also has data relating to existing
conditions in the files in the form of quantitative Rooted-Nested transect data from 2006-2007,
qualitative Public Land Health Standards from 2000-2001, and Lentic Riparian conditions from
1998 and 2001.
Examination of the body of available data reveals that, for the project area at the overall landscape
level, vegetative conditions are meeting desired conditions. However, there are isolated areas of
concern noted by FS/BLM personnel, specifically at bed grounds and trailing “choke points.” More
detailed descriptions of the data can be found in Affected Environment of the Water and Vegetation
sections in Chapter 3.
Existing Conditions for Bighorn: Figure 1-5 displays current grazing allotments and bighorn sheep
summer range. There are currently about 41,400 acres of potential mapped overlap in the Silverton
Landscape. This existing condition is undesirable due to potential for contact between domestic
sheep and wild sheep leading to the possibility of disease transmission between the two species.
Existing Conditions for Wilderness: Figure 1-6 displays where grazing allotments and wilderness
overlap. Because the desired conditions for wilderness are related primarily to vegetation conditions,
the conclusions for existing wilderness conditions are generally the same as for vegetative existing
20

conditions. However, there were isolated locations within wilderness (Highland Mary Lakes and
Continental Divide Trail) where conditions were noted to be of concern.
Purpose and Need for Action_______________________
The purpose of this action is to continue to authorize livestock grazing on all or portions of the
Silverton Landscape in such a manner that will meet or move existing resource conditions toward
desired conditions, and be consistent with the Forest Plan/RMP direction, standards and guidelines.
The site-specific need for those areas where desired conditions are currently being met is to maintain
or improve current conditions. The site-specific “need for change” for those areas which are not
meeting or moving toward desired conditions is to bring existing conditions up to, or moving
towards the desired conditions in a timely manner.
The site-specific “need for change” in vegetative conditions is to implement grazing management
practices that will improve conditions at the isolated sites that were noted to be in undesirable
condition.
The “need for change” regarding bighorn is to minimize the likelihood of contact between wild
sheep and domestic sheep and goats. This is easily and most effectively dealt with on allotments that
are not currently active by closing the allotments to domestic sheep grazing (Little Molas/West
Needles, Needles Mountains, and Minnie Gulch). The four active allotments with mapped overlap
between wild sheep and domestic sheep that would remain open to sheep grazing (Picayne/Mineral
Point, Engine Creek/Deer Creek, Eureka, and Gladstone) could meet desired conditions for bighorn
sheep through application of design criteria and maintaining current domestic sheep distribution
patterns.
The “need for change” in proposing to close the West Lime Allotment is that it would not meet
desired conditions for vegetation if it were to be re-stocked with livestock. This is due to the fact that
there is little suitable range in the allotment that is practical to be used. Most of the mapped suitable
range is in the high-use recreation areas of South Mineral Creek and Ice Lakes/Clear Lake Basins.
Attempts to graze the remaining suitable range would likely result in over-utilization leading to
unsatisfactory conditions. In addition, Ice Lakes/Clear Lake Basins have been used regularly in
summer by small numbers of bighorn sheep the past few years. It is unknown which herds these
bighorn sheep are coming from and thus restocking this allotment could create a substantial risk for
contact between domestic sheep and bighorn sheep.
This proposed action and analysis is needed at this time because in the early 1990’s, the courts
determined that livestock grazing permits should not be re-issued without sufficient NEPA analysis.
This put many livestock operations at risk until such time as these analyses could be completed. In
response, Congress passed the Rescissions Act of 1995 (P.L. 104-19 1995), which provided for
continuation of permit issuance if the only reason they could not be issued was lack of a NEPA
analysis. The Act directed the FS/BLM to develop and adhere to a schedule for completion of the
analyses. This project analysis is being undertaken as part of the schedule (SJNF 2005) that was
developed for the San Juan Public Lands.
21

Figure 1-4. 2008 Data Collection Points
22

Figure 1-5. Bighorn Overlap
23

Figure 1-6. Wilderness Overlap
24

Proposed Action _________________________________
The proposed action is to continue to permit livestock grazing by incorporating adaptive
management strategies on eight active allotments (Deer Park, Elk Creek, Engine Creek/Deer Creek,
Eureka/California Gulch, Gladstone, Maggie Gulch, Picayne/Mineral Point, and Red Mountain), to
close four allotments (Little Molas/West Needles, Minnie Gulch, Needle Mountains, and West
Lime), and to convert two allotment to forage reserve status (Flume and Graysill). Also included in
the proposed action are specific actions included in Site-Specific Design Criteria, and other general
Design Criteria as described in Chapter 2.
Adaptive Management is defined as, “The process of making use of monitoring information to
determine if management changes are needed, and if so, what changes, and to what degree,”
(Quimby 2006). The proposed action is designed to meet or move toward desired conditions in
rangeland health, vegetation, and watershed conditions relative to livestock grazing within the
landscape, and is designed to meet Forest Plan/RMP direction, standards, and guidelines.
Chapter 2 presents a more detailed description of the proposed action on p.28.
Decision Framework ______________________________
Given the purpose and need, the deciding official reviews the proposed action and the other
alternatives in order to make the following decisions:
1. Will livestock grazing proceed as proposed, as modified, or not at all – on all or part of the
Silverton Landscape? The Silverton Watershed Allotment is within the physical boundaries
of the project area, but has previously been closed to grazing and is not being re-considered
for grazing in this analysis.
2. If livestock grazing proceeds: Where will on-the-ground activities occur, and what types of
associated activities will occur?
3. What mitigation measures or design criteria and monitoring requirements will the FS/BLM
apply to the project?
4. If Adaptive Management is chosen, how will monitoring be used to guide when adaptive
options will be activated?
The responsible official may choose an alternative in its entirety, may modify an alternative, or may
craft a decision merging specific components from different alternatives.
Public Involvement _______________________________
The proposal was listed in the San Juan Public Lands Quarterly Schedule of Proposed Actions
beginning in January 2009, which was available on-line and through quarterly mailings. Two
permittee scoping meetings were held on January 30, 2009 and March 19, 2009 for those who hold
livestock grazing permits on this landscape. The proposal was also provided to the public and other
agencies for comment during scoping beginning in February 2009, through a scoping letter and press
release and which resulted in newspaper articles. In addition, as part of the public involvement
process, the Forest Service sent notification to area Tribes, Chapter Houses, and Pueblos.
Written scoping responses were received from 24 sources. Using the comments and concerns from
the public, organized groups, other agencies, and internal specialists, the interdisciplinary team
developed a list of issues to address in this analysis.
25

Issues __________________________________________
The FS/BLM separated the issues into two groups: significant and non-significant issues. Significant
issues are defined as those directly or indirectly caused by implementing the proposal. Significant
issues also usually result in the generation of an alternative, design criteria, or mitigation measure
that addresses that issue.
Non-significant issues are identified as those: 1) outside the scope of the proposed action; 2) already
decided by law, regulation, Plan, or other higher level decision; 3) irrelevant to the decision to be
made; 4) conjectural and not supported by scientific or factual evidence; or 5) fully supportive of, or
addressed by, the proposed action . The Council for Environmental Quality NEPA regulations
require this delineation in Sec. 1501.7, “…identify and eliminate from detailed study the issues
which are not significant or which have been covered by prior environmental review (Sec.
1506.3)…” A list of non-significant issues and reasons regarding their categorization as nonsignificant
may be found in the project record.
The FS/BLM identified five significant issue topics generated from scoping. Additionally, one
tracking issue will be analyzed. Tracking issues are a sub-set of non-significant issues, and are
defined as those not identified as significant issues, but deemed important enough to track through
the analysis and disclose impacts.
Indicators which can be used to compare impacts between alternatives are listed for each issue.
1) Soil/Water: Improper trailing and bedding of livestock has sometimes led to
erosion (including trail tread damage and terracing), and water quality issues
(sedimentation, increased dissolved metals, and fecal contamination).
Indicators for comparing alternatives: Acres of mineralized soil grazed;
monitoring measures (PFC), management of sheep reflected by Watershed
Design Criteria.
2) Vegetation: Improper trailing and bedding of livestock has sometimes led to
undesirable species composition and damage to delicate alpine vegetation.
Indicators for comparing alternatives: Acres grazed; monitoring measures
(RHM and LHA); management of sheep reflected by Design Criteria;
narrative descriptions.
3) Recreational Experience: Sheep bands have sometimes negatively impact the
recreational experience by noise and smell, by encounters with unruly herd
dogs, by creating a non-wilderness experience, by reducing wildflowers, and
by causing trail tread damage and braided trails. Indicators for comparing
alternatives: Management of sheep reflected by Recreation Design Criteria;
monitoring measures (photopoints); narrative descriptions.
4) Wildlife: Domestic sheep could transmit disease to bighorn sheep, compete for
forage with wildlife (bighorn sheep, ptarmigan, elk), and could damage
Uncompahgre fritillary butterfly habitat. Indicators for comparing alternatives:
Management of sheep reflected by Wildlife Design Criteria; acres of open
(active or vacant) allotments overlapping with bighorn sheep summer range;
acres of butterfly restriction areas.
5) Socio-Economics: Loss or substantial curtailment of permitted grazing could lead
to major economic and social damage to permittees, as this is their cultural
26

heritage and sole financial support for most of them. Indicators for comparing
alternatives: qualitative narrative description.
6) Cultural Resources (tracking issue): Cultural resources impacts were not
identified as a significant issue because no adverse impacts to them from
grazing have been identified. There are no alternatives or design criteria that
were developed specifically to minimize cultural impacts, and impacts are
generally the same across all alternatives. However, because of the importance
of the cultural resources in the Silverton landscape, and because of statutory
requirements, cultural resources will be analyzed and impacts will be
disclosed. Indicators for comparing alternatives: Management of sheep
reflected by Design Criteria; narrative description.
27

CHAPTER 2 - ALTERNATIVES
This chapter describes and compares the alternatives considered for the Silverton Landscape Grazing
Analysis. It includes a description of each alternative considered. This section also presents the
alternatives in comparative form, defining the differences between each alternative and providing a
clear basis for choice among options by the decision maker and the public.
Some of the information used to compare the alternatives is based upon the design of the alternative
(e.g., allotments to be closed) and some of the information is based upon the environmental, social
and economic effects of implementing each alternative (e.g., the effects on vegetative conditions).
Alternative 1 – No Action ___________________________
Under the No Action/No Livestock Grazing Alternative, no livestock grazing would be permitted on
any of the allotments in the landscape. “No action” is synonymous with “no livestock grazing” and
means that livestock grazing would not be authorized within the project area. Following current
direction, existing permits would be phased out after giving permittees notice as provided for in
Forest Service policy (FSH 2209.13, R2 ID, Chapter 10, section 16.1) which says that “…the
authorized officer shall provide one year’s written notice before the modification takes effect, except
in emergency situations.” According to direction given in FSH 2209.13, R2 ID, Chapter 90, section
94.1, “the ‘no livestock grazing’ alternative will always be fully developed and analyzed in detail”
and is therefore considered a fully viable alternative in this analysis. Improvements such as corrals
would eventually be removed as time and funding allow. This alternative provides an environmental
baseline for evaluation of the action alternatives.
Design Criteria for Alternatives 2 and 3 ______________
The Forest Service uses many measures to reduce or prevent negative impacts to the environment in
the planning and implementation of management activities. The application of these measures
begins at the planning and design phase of a project. The Forest Plan/RMP standards and guidelines
and the direction contained in the Watershed Conservation Practices Handbook (FSH 2509.25) and
the Range Management Handbook (FSH 2200) are the first protection measures to be applied to the
project. These sources are incorporated by reference and are not reiterated here. Other Project
Design Criteria are then developed, as the need is identified by the FS/BLM specialists and
authorized officer.
Some of the design criteria below have been used for years or are commonly used practices
throughout the western United States and have been found to be effective in reducing potential
impacts. Beside the commonly used practices, additional practices concerning the management of
contact between domestic sheep and goats and Rocky Mountain bighorn sheep are included. Many
of these recommended practices were taken from Wild Sheep Working Group Initial Subcommittee,
Recommendations for Domestic Sheep and Goat Management in Wild Sheep Habitat (WAFWA,
2007).
28

Depending on the alternative selected, the applicable design criteria become a part of the projectlevel
decision and the resultant Allotment Management Plans. The list of design criteria has been
organized into logical categories. Each bullet statement applies to a specific action alternative as
indicated by an “x” in the far right columns.
Table 2-1. Project Design Criteria for General Management
of Permitted Domestic Sheep
Alternative
Livestock Herding* 2 3
Livestock will be herded using the “open herding system” and distributed across the allotment(s) in order
to achieve proper grazing utilization of key forage species. (1.1)
x x
Repeated trailing by sheep across areas is to be avoided. (1.2) x
The “close herding” of sheep and the driving of bands to camp during the noon hour or at night are
prohibited. (1.3)
x x
Move sheep to a new grazing area every 5-7 days. (1.4) x
Snow bank areas will be avoided until they are dry enough to prevent livestock trampling impacts. (1.5) x x
Permittees will spend as much time as needed to move livestock away from areas of concern (meadows,
riparian areas, key areas, and so forth) and into areas of normally light use, provided that such herding
does not result in increased potential for contact. This benefits permittees since it allows livestock to
make use of forage that otherwise will not be grazed before allowable use standards are met in the key
areas and the livestock are required to be removed from a pasture. (1.6)
Livestock grazing will be managed in riparian areas and willow carrs (a wetland willow thicket) to
maintain or achieve mid-seral or higher condition to provide cover and forage for prey species within
Canada lynx habitat (from Ruediger et al. 2000). (1.7)
Livestock will be moved away from water sources after animals have finished drinking. The sheep will
not be trailed to and from water. (1.8)
All trailing on federal land for ingress and egress to the permitted allotment will be within the period of
use specified in the permit. (1.9)
Livestock grazing systems will be designed to maximize the opportunity for plant regrowth and recovery,
by focusing on the frequency of defoliation, the intensity of defoliation, and the timing and duration of
livestock use. (1.10)
Grazing schedules will be developed so that areas are used at different times of the year if at all
possible. Grazing schedules will be developed in the Annual Operating Instructions based on the
Grazing Response Index and/or an evaluation of grazing and trailing from the previous season and the
resource conditions of the current season. Negative GRI scores are to be avoided and will be corrected
by changing any or all of the following: the season of use, allowable use standard, residual stubble
height, stocking rate, timing of livestock use. (1.11)
x x
x x
x
x x
x
x
29

Alternative
Livestock Bedding 2 3
Sheep will be bedded on new ground after two nights and moved to fresh feed daily in accordance with
the current routing schedule. (1.12)
x x
Sheep will be bedded on uplands or rocky ground, where possible. (1.13) x
Sheep bedding and salting will not occur in Uncompahgre fritillary butterfly habitat. (1.14) x
Sheep should be bedded away from any running stream, spring, lake, system trail, campground, picnic
ground, and the remains of historic structures. There may some exceptions due to topography on the
allotment but these will be approved in advance by the Forest Officer. (1.15)
Bedgrounds in some areas may be closed or relocated in the Annual Operating Instructions on an
annual basis, based on impacts. Locations of and frequency of use will be one of annual monitoring
indicators. (1.16)
Herders will be vigilante to domestic movement off of bedgrounds during the night due to lunar phase or
predation. These strays will be located and returned to the band the next day. (1.17)
x
x
x
Alternative
Disposal of Dead Livestock 2 3
When an animal covered by this permit dies from any cause, including contagious or infectious disease,
the carcass must be buried in a location greater than 200 feet from water, out of view of roads or trails,
and away from any areas of significant public use, within 24 hours of discovery, or notification by forest
personnel. Off road travel or the use of heavy equipment must be authorized by the Forest Service, in
advance. The preferred method for burial is simply by the use of a pick and shovel. If an animal dies or
is killed from any other cause, the carcass must be moved to a location greater than 200 feet from water,
out of view of roads or trails, and away from any areas of significant public use, within 24 hours of
discovery, or notification by forest service personnel. Carcasses may be burned under certain
circumstances when authorized by forest service personnel on a case by case basis. (1.18)
x x
Alternative
Herder Camps 2 3
Sheep herder camps will be moved every 5 to 10 days. (1.19) x x
Camps will be placed at least 100 feet from live water. (1.20) x x
Camps will be kept and left clean. All flammable refuse will either be burned or packed put. Unburnable
refuse, including cans, bottles, etc., will be packed out. (1.21)
x x
Camps will be placed at least 200 feet from any system trail. (1.22) x x
Sheep herders will not be allowed to excavate campsites. (1.23) x
Sheep herders will not be allowed to cut krummholz (dwarf spruce trees at timberline) for firewood.
(1.24)
All fires built for any purpose by the permittee and/or herder will not be left unattended and will be
completely extinguished. Each camp must be equipped with a serviceable shovel and ax. During
periods the FS/BLM has enacted fire restrictions, these restrictions will be observed. (1.25)
x
x x
30

Alternative
Working Dogs and Pack Stock 2 3
Working dogs will be under the herder’s control and must be non-threatening to recreation or other
visitors. Threatening for this purpose will be defined as a dog that comes within approximately 20 feet of
a person in an aggressive manner, (i.e. barking and snarling) and continues to follow the person as they
attempt to retreat. This applies only if the visitor is not within the bounds of the grazing sheep band.
(1.26)
Working dogs that do not meet the above requirements will be immediately removed by the permittee
from the Analysis Area. (1.27)
Signs will be placed at trailheads giving public notice of the presence of sheep herder working dogs in
the Analysis Area (posted by the FS/BLM). (1.28)
There will be an upper limit on the maximum number of dogs that will be allowed to be used in
conjunction with the sheep operation. No more than eight dogs in combination ( guard dogs and border
collies or other working dogs ) will be allowed per sheep band. (1.29)
Pack and saddle stock as allowed in the permit are to be used for management of permitted livestock
only. Stock may be waived only when the entire grazing permit is waived. (1.30)
x
x
x
x
x x
Alternative
Animal Damage Management 2 3
Animal damage management activities will be conducted in accordance with both Federal regulations
and State law. Requests for assistance will be done in compliance with the current Animal and Plant
Health Inspection Service (APHIS) Animal Damage Management Plan (for example, APHIS 2005) and
must be in compliance with the Forest Plan/RMP. (1.31)
Predator control (i.e., black bears, mountain lions, bobcats, and coyotes) will not be conducted without
following the correct State, APHIS, and Forest Service/BLM procedures. These procedures will be
provided to permittees in writing (part of the Annual Operating Instructions). (1.32)
It is illegal to kill a grizzly bear, Canada lynx, wolverine, wolf, or any birds of prey. Publications will be
made available to permittees to help distinguish the difference between certain protected species and
several look-alike species as follows:
Grizzly bear and black bear – a bear identification sheet will be given to permittees.
Canada lynx and bobcat – an identification sheet will be given to permittees
Wolves and dogs – an identification sheet will be given to permittees(1.33)
x x
x x
x x
31

Alternative
Noxious Plants/Invasive Species 2 3
Any hay, straw or other feeds used on the allotment will be either certified as being free of noxious plants
(also called noxious weeds), or will consist of heat-treated pelletized feeds. (1.34)
Any seed used on the allotment will be tested for “all states noxious weeds” according to Association of
Official Seed Analysts (AOSA) standards and will be certified by a Registered Seed Technologist or
Seed Analyst as meeting the requirements of the Federal Seed Act (7 U.S.C. Chapter 37: Sections
1551-1611) and the Rules and Regulations of the Colorado Seed Act pursuant to 35-27-101 through
125, C.R.S. (1993 Supp. as amended by Senate Bill 93-17). (1.35)
Conduct prevention, control, and eradication strategies for targeted invasive plant species, utilizing
integrated weed management techniques through implementation of the San Juan NF Invasives Action
Plan. (1.36)
Permittees will make every effort to ensure that livestock do not contribute to the transport of noxious
plants onto the allotment(s). Permittees will be given identification information on State of Colorado
“noxious weeds” during annual meetings with the FS/BLM. The Colorado noxious weed list is available
on the internet at: http://www.ag.state.co.us/CSD/Weeds/statutes/weedrules.pdf
Noxious plant photos are available at:
http://kiowa.colostate.edu/cwis109/noxious_weeds/Noxious_weeds.cfm (1.37)
Note: in addition to Project Design Criteria, the following are recommended practices that will be discussed with
permittees at the time of the Annual Operating Instructions meeting with agency personnel:
Permittees are asked to help in locating noxious plant sites and reporting them to the Agency Officer. Permittees
willing to assist in treating noxious plants should communicate with the Agency Officer before taking any action.
Livestock coming onto the Forest/BLM from lands known to contain noxious plants should be held on clean forage or
fed weed-free hay for several days to allow the majority of seeds to pass before turn on.
Any equipment used in the transport of livestock, including horse trailers and stock trucks, should be washed before
coming onto the allotment if they have been used in areas where noxious plants were present.
x x
x x
x
x
Alternative
Access and Travel Management 2 3
Permittees are required to abide by all FS/BLM road and trail restrictions and closures. Use of closed
roads, and use of motorized equipment in areas designated as non-motorized requires a separate road
use permit to be obtained prior to use. (1.38)
x x
Alternative
Wilderness 2 3
Livestock will be managed within wilderness to minimize impacts on the wilderness environment and to
minimize potential conflict with other users of the area. (1.39)
x x
Alternative
Information Notifications 2 3
Provide the public information about the presence of working dogs and the “Do’s and Don’ts” when
recreating near domestic sheep bands. (1.40)
Information will be made available at the Silverton Columbine Ranger District/Field Office about livestock
grazing rotation schedules so that those recreation visitors who wish to, may avoid encounters with
domestic sheep and the resultant activities. (1.41)
x
x
32

Alternative
Permittee Instructions* 2 3
Annual Operating Instructions (AOIs) will be provided concerning proper management practices, so that
this information can be passed on to non-English speaking/reading herders (if applicable). Permittees
will be responsible for ensuring that their herders understand and comply with FS/BLM requirements.
(1.42)
The earliest turn on date and latest removal date will be based on allotment conditions relative to wet
soils or snow, range readiness, vegetative phenology, and on minimizing conflicts with other uses.
These annual dates will be communicated through the AOIs. Even when these conditions are met, the
dates of livestock grazing will not exceed June 30 – Sept 20. (1.43)
x
x
Alternative
Monitoring* 2 3
Permittees are responsible for monitoring the following: livestock numbers; pasture entry and exit dates;
allotment entry and exit dates; and maintenance activities for assigned improvements. This information
will be furnished to the agency office within 30 days of livestock removal. This information will be verified
by periodic agency inspections. (1.44)
Permittees will keep a weekly log of specific locations where they encounter certain species of wildlife
and will turn it in to the Agency Officer upon request or at the end of the grazing season. The species to
be reported will include special status species such as bighorn, lynx, wolverine, etc. (1.45)
Agency personnel will conduct annual permit administration consisting of monitoring such compliance
with AOIs, general livestock locations and use levels, plant phenology of important forage species,
noxious weed mapping, soil conditions, riparian conditions and water quality, and impacts from other
uses. (1.46)
Any monitoring outcome, when part of the five-year interval monitoring, that does not meet Desired
Condition will require the application of adaptive management strategies to livestock grazing practices to
recover and maintain desired conditions, when livestock are a contributing factor to the condition. (1.47)
x x
x
x x
x
Alternative
Heritage Resources 2 3
All persons associated with operations under this authorization must be informed that any objects or
sites of cultural, paleontological, or scientific value such as historic or prehistoric resources, graves or
grave markers, human remains, ruins, cabins, mining relics, rock art, fossils, or artifacts shall not be
damaged, destroyed, removed, moved, or disturbed. If in connection with operations under this
authorization, any of the above resources are damaged, the proponent shall immediately suspend all
operations that might further damage such materials and notify the Columbine Public Lands authorized
officer. (1.48)
Areas of intensive activity such as salt licks, bedding areas, and herder camps will not be located within
100 feet of the boundaries of previously identified significant cultural resources. Range managers will
work with archaeologists to select locations that avoid known significant cultural resources and are likely
to avoid unidentified sites in areas that lack cultural resource surveys. (1.49)
*
Note: See “Project Design Criteria to minimize contact between Rocky Mountain bighorn sheep and domestic sheep”, below for
further instructions.
x
x
33

Table 2-2. Project Design Criteria to minimize contact between Bighorn
and Domestic Sheep
Alternative
Risk Assessments (in the project record) 2 3
High Risk Allotments
Permitted domestic sheep and goat grazing will not be authorized within high risk areas of the allotment.
In most instances, domestic sheep may still be authorized within the allotment but management will
ensure routing and other design criteria to avoid the high risk areas. This can be accomplished through
adaptive management tools. (2.1)
Moderate Risk Allotments
Permitted domestic sheep and goat grazing may be authorized. However, design criteria will still be
implemented to strive to reduce the potential for contact even farther. (2.2)
Low Risk Allotments
Permitted domestic sheep and goat grazing may be authorized. Permitted domestic sheep grazing will
be focused towards these areas. However, design criteria should still be implemented to strive to reduce
the potential for contact even farther. (2.3)
x
Alternative
Minimization of Threat of Disease Transmission 2 3
Follow the response protocol for confirmed contact or threat of impending contact between permitted
domestic sheep and bighorn:
Permittee
The permittee or their agent will contact the Columbine Ranger District/Field Office range personnel
immediately if bighorn come into contact or there is a threat of impending contact with domestic sheep.
Contact information as well as phone numbers will be included in the Annual Operating Instructions.
(2.4)
Permittees authorized to graze in areas rated as “Moderate Risk”, will require herders to carry and use a
“SPOT satellite messenger” to allow for the immediate notification and location of domestic sheep and
bighorn contact or impending contact due to unforeseen movements of the domestic sheep and/or
bighorn. Information about the “SPOT” device is available at: http://www.findmespot.com/en/ (2.5)
As an immediate response, the permittee and/or the herders will be authorized to haze bighorn that are
threatening to make contact with domestic sheep. This will be accomplished through an agreement
between the grazing permittee and the CDOW. The agreement will include circumstances requiring
hazing response, appropriate type of hazing and reporting requirements. (2.6)
Forest Service/BLM
When informed about potential bighorn/domestic sheep contact, the FS/BLM will contact the permittee
immediately notifying them of the situation. At this point, the FS/BLM and the permittee will implement
other design criteria if needed to prevent or reduce the threat of impending contact. At this time an
alternate plan of grazing for the remainder of the season, “flexible management” may be implemented to
strive to prevent contact from occurring. Adjustments may be extended to upcoming seasons. (2.7)
Concurrently, as contact or the threat of contact is made known, the FS/BLM will contact the CDOW
(contact information will be provided to the FS and the permittee prior to the grazing season). Actions
that the CDOW will take is at their discretion concerning wildlife health intervention and management of
the bighorn. CDOW will inform the FS/BLM if the situation is rectified and discussion/planning will occur
with the permittee to implement an alternate management strategy if needed. The CDOW may
implement post contact monitoring. (2.8)
x
34

Alternative
Minimization of Threat of Disease Transmission 2 3
The FS/BLM will make the particular domestic sheep band (and the area) a high priority for monitoring to
determine if there is bighorn activity in the area or if the risk assessment should be revisited. (2.9)
The FS/BLM will work with CDOW to prioritize and implement coordinated annual monitoring of bighorn
sheep individuals and populations using the upper Animas River Basin. Monitoring activities could
include coordinated ground counts, aerial counts, radio/GPS collars, etc. Implement a system for
immediate cross-agency sharing of bighorn sighting reports to keep all parties informed about bighorn
use of the upper Animas River Basin. (2.10)
Annually, in conjunction with CDOW and the permittee, review the effectiveness of Design Criteria
implementation and new information such as recent bighorn sightings. Update the allotment Risk
Assessment if necessary, and make adjustments to upcoming grazing accordingly. These adjustments
may include adjacent BLM and/or USFS administrative units, depending on availability and feasibility.
Feasibility includes the permittees’ needs as well as the administrative availability of allotments on other
administrative units. Adjustments will be focused on reducing the risk of interactions if the risk has
increased to an unacceptable level. (2.11)
Sheep and goat allotments with mapped overlap of bighorn summer range will be evaluated for closure
when/if permits are relinquished back to the FS/BLM. (2.12)
Herding
At least one herder is required to be with the sheep. The main flock will never be left unattended, except
at night, and short periods when the herder is accomplishing other tasks in the immediate area. A
herder must remain in the camp during the night. (2.13)
Trailing of domestics will happen as much during the middle of the day to avoid bighorns as possible. In
certain areas this will not be possible due to conflicts with recreation users. (2.14)
Sick or diseased domestic sheep and goats – post turnout
Injured, sick or diseased livestock will not be left behind but will be removed or terminated and disposed
of according to the “Disposal of Dead Livestock” requirements below and in accordance with State
Statute. Sick or diseased animals will be removed or otherwise eliminated when identified. (2.15)
Sick or diseased domestic sheep and goats – pre turnout
It is imperative that permittees maintain a high certainty of domestic animal health in their permitted
stock. Permittees/Herders will take appropriate measures to prevent turnout of sick or diseased domestic
sheep and goats on grazing allotments, on trailing routes, or in weed control or pack-stock situations. It
should also be recognized that “healthy-appearing” domestic sheep and goats may still carry pathogens
(harmless to them) that can be transmitted to wild sheep. (2.16)
Sick or diseased bighorn sheep
Sick bighorn sheep or carcasses must be reported as soon as possible to the Columbine Ranger
District/Field Office range personnel. Agency personnel will then notify the CDOW as soon as possible.
(2.17)
x
x
x
x
x
x
35

Alternative
Minimization of Threat of Disease Transmission 2 3
Salting
Every effort should be made to deny bighorn access and consequent attraction to the domestic sheep
salting activities. Leaving available salt or excess salt residue in the soil or on rocks or tubs presents a
salt source that may attract bighorn and may even train bighorn to follow the domestic sheep bands in
search of salt. (2.18)
Blocks of salt will be allowed and, if used, will be kept with the domestic sheep at all times. Salt will not
be left behind when the domestic sheep are moved. (2.19)
Salt or supplement will be placed only on rocky knolls, well-drained sites or in timber where excessive
trampling will not destroy plant growth. Salt or supplement will not be placed closer than ¼ mile to
streams, springs, water developments, or other wetlands without prior approval of the Agency Officer.
Salt or supplement will not be placed near trailheads, on open roads, in natural travel routes, passes,
parks, meadows, in areas of concentrated public use, or in other areas where such placement is liable to
result in conflicts with other public land users. Salt or supplement will not be placed within tree
regeneration areas where the smallest trees are less than three feet tall. (2.20)
Herder education
It is of utmost importance that the permittees spend as much time as necessary teaching the herders the
requirements attached to the grazing permit, annual operating instructions and all the applicable Project
Design Criteria included here. With the implementation of “adaptive management,” areas authorized for
grazing as well as routing patterns and schedules may change from year to year and even within the
year, along with other management techniques. Following procedures to avoid contact and prompt
accurate reporting of bighorn/domestic sheep contact or impending contact is essential. Herders are
crucial to ensuring proper management and in maintaining compliance to an exacting standard.
Ultimately the responsibility rests upon the permittees to ensure compliance is being achieved. (2.21)
General wildlife sighting reporting
Permittees will be required to report wildlife sightings on the annual actual use form that must be turned
in each fall to the FS/BLM; however bighorn sightings in the proximity of the domestic sheep band must
be reported immediately. If bighorn are seen near or on any FS/BLM sheep and goat allotment, follow
protocol above. (2.22)
Planned domestic sheep estrus cycle
The planned breeding season for the domestic sheep operation will not occur during the permitted
grazing season on federal land. This is to lessen the attraction of bighorn rams to domestic sheep ewes
in estrus. (2.23)
x
x
x
x
36

Alternative
Permitted domestic sheep stray management 2 3
Accountability of Permittee
Extensive efforts will be made by the permittee to remove every authorized domestic sheep from the
Analysis Area following the grazing season. All sheep must be accounted for (dead or alive) as they
enter and exit each allotment, and as they exit the Analysis Area at the end of the season. Special
attention should be given to accounting for sheep at all times. If sheep are unaccounted for, diligent
efforts should be made to locate them as quickly as possible. If the FS/BLM feels that appropriate efforts
are not being implemented, a count-on/count-off inventory will be required as a condition of operation.
(2.24)
Permittees will be required to respond to reports of stray domestic sheep within 24 hours of notice by the
FS/BLM. Stray domestic sheep will be gathered or disposed of within 72 hours of notification. A followup
report (verbal or written) will be provided to the FS/BLM on time, date and action taken to resolve the
matter; within four days from the notice given by the FS/BLM. (2.25)
Driveways and trails between grazing areas will be revisited to ensure no stray domestics have been left
behind. (2.26)
Trailing
Random on-site compliance monitoring to minimize strays will be conducted by the Forest Service.
Trucking of domestic sheep and goats is preferred to trailing except in situations where risk of contact is
possible (i.e., trucking drop off points in subpopulation areas). In most cases trucking reduces the
chance of stray domestics, and lessens the chance of opportunistic contact by wandering wild sheep.
Domestic sheep will be kept in a tight group during trailing. (2.27)
Domestic sheep identification
Permittees will be required to freshly mark (sheep paint) their sheep before they enter onto the National
Forest/BLM. The FS/BLM will coordinate with the permittees annually with specific information regarding
color of paint used in marking their sheep, brands used, ear tags used and colors, earmarks, and other
distinguishing marks or characteristics that may be used in identifying their sheep. In the event, a
permittee does not wish to paint brand their sheep due to conflicts with marketing dye free wool, that
permittee will be assigned a region that they will be responsible for responding to all reports of stray
domestic sheep ( even if it is not their sheep ). (2.28)
Permit Action
Repeated non-compliance with domestic sheep stray management will result in appropriate permit
action. (2.29)
x
x
x
x
x
x
37

Alternative 2 – Current Management_________________
Under the Current Management Alternative, livestock grazing would continue with current AMP’s
or, in the absence of such, a plan, or if the existing plan is not being followed for a variety of
reasons, under the Annual Operating Instructions (AOI’s). As provided for in Forest Service policy
(FSH 2209.13, R2 ID, Chapter 90, section 94.1), “Current management will also be analyzed in
detail as an alternative to the proposed action if current management will meet the stated purpose
and need for action. This alternative is based on the current management action being implemented.
Current management direction may be contained in an AMP, AOI, a biological opinion, or a
combination thereof.”
Livestock grazing would continue to be authorized as it has been in the recent past using a predefined
number of livestock, seasons of use, and pasture rotation systems. For the allotments in this
analysis, this would be as shown in Table 2-3.
Allotment
Table 2-3. Current Grazing Management by Allotment
Grazing
System
Permitted
Livestock
Numbers
AUM’s
Season
Deer Park rotation 1000 413 7/16-9/20
Elk Creek rotation 1000 446 7/11-9/15
Engine/Creek Deer Creek rotation 1000 513 7/1-9/15
Eureka/California Gulch rotation 1275 569 7/10-9/15
Gladstone rotation 924 351 7/10-9/5
Maggie Gulch rotation 1000 433 7/11-9/14
Picayne/Mineral Point rotation 1031 460 7/10-9/15
Red Mountain rotation 1000 513 7/1-9/15
Permitted livestock numbers would not change. For sheep allotments, permitted numbers refer to the
number of ewes, each of which may have one or more lambs. Existing improvements would
continue to be maintained as assigned in Term Livestock Grazing Permits and may be re-constructed
once the useful life has been met and the need identified. New improvements would not be
developed unless they are authorized in a NEPA decision. Sheep allotments typically do not have
structural improvements except for corrals and loading facilities.
Design Criteria Those design criteria as indicated in Tables 2-1 and 2-2 (p.29+) by an “x” in the
Alternative 2 column are included as part of Alternative 2. These criteria apply to all active
allotments across the landscape at all times.
Alternative 3 – Adaptive Management/Proposed Action_
The proposed action is to continue to permit livestock grazing on the Silverton Landscape by
incorporating adaptive management strategies that will allow the lands within the landscape to meet
or move towards meeting Forest Plan/RMP direction standards, and guidelines and desired
conditions identified in this EA. Adaptive management is a process where land managers implement
management practices that are designed to meet Forest Plan/RMP standards and guidelines, and
would likely achieve the desired conditions in a timely manner. However, if monitoring shows that
desired conditions are not being met, or if movement toward achieving the desired conditions in an
acceptable timeframe is not occurring, then an alternate set of management actions, as described and
evaluated under this NEPA analysis, would be implemented to achieve the desired results. Adaptive
Management is designed to be flexible in nature, and is based on conditions on the ground; not
38

egulated by fixed livestock numbers or seasons of use. It can be compared to a performance-based
contract that is written with specifications for the end results, rather than written with detailed
specifications on how to accomplish the job.
Under adaptive management, the proposed action is a set of specific initial actions that are chosen as
the starting point believed to best meet or move toward desired conditions in rangeland health,
vegetation composition and abundance, and watershed conditions relative to livestock grazing within
the landscape, and is designed to meet Forest Plan standards and guidelines. This initial course of
proposed action is described below:
The proposed action would reissue eight grazing permits on the following active allotments:, Deer
Park, Elk Creek, Engine Creek/Deer Creek Eureka/California Gulch, Gladstone, Maggie Gulch,
Picayne/Mineral Point, and Red Mountain.
Four vacant allotments would be closed to grazing; Little Molas/West Needles, Minnie Gulch,
Needles Mountains, and West Lime.
Two vacant allotments would be designated as forage reserves: Flume and Graysill.
Incorporate Design Criteria as described below.
Design Criteria for Alternative 3
Design Criteria Those design criteria as indicated in Tables 2-1 and 2-2 (p.29+) by an “x” in the
Alternative 3 column are included as part of Alternative 3. These criteria apply to all active
allotments across the landscape at all times.
Site-Specific Design Criteria for Alternative 3
The design criteria above are applicable to the entire project area. During 2008 field analysis, some
specific locations were identified as having a “need for change”. These sites were determined to
have a need for change if they do not currently meet the Desired Condition. See Figure 2-1.
Deer Park Allot
• Grazing rotations will be designed to minimize conflict with recreation use to the extent possible
in the following areas: Spencer Basin and Highland Mary Lakes, especially during high traffic
times, holiday weekends, wildflower season etc. (S-S.1)
• Reduce the time spent on the west side of the Highland Mary Lakes Basin – in order to do so,
make up more days on other areas of the allotment like Spencer Basin, Kendall Gulch, Deer
Park, and the area on the east side of the Highland Mary lakes. ( S-S.2)
• Move the allotment boundary with Elk Creek Allotment to the top of the basin east of Highland
Mary lakes so that the Deer Park band can use the east side of the lakes basin. (S-S.3)
• No bedding within ¼ mile of the lakes (S-S.4)
After 2-3 grazing seasons, re-visit the bed grounds. If still not in satisfactory condition:
• Change ingress/egress route to Kendall Gulch, improving rotation scheme. (S-S.5)
• And/or change the class of livestock to yearlings. (S-S.6)
After 2-3 more grazing seasons, re-visit the bed grounds, If still not in satisfactory condition:
• Remove the Highland Mary Lakes basin from grazing and reduce the total grazing season by
appropriate number of days. (S-S.7)
39

Elk Creek Allot
• Do not use the Continental Divide Trail #813 as a driveway (except with ingress/egress to the
Cunningham Corrals) and minimize the number of times sheep cross the trail. Keep sheep away
from the trail as much as possible. (S-S.8)
Engine Creek/Deer Creek
• The boundary of the Engine Creek/Deer Creek Allotment would be altered to eliminate all area
southwest of Highway 550 (except for ingress/egress to the Lime Creek corrals), and to
eliminate the area around Coal Bank Pass. Area would be added on the northeast side to allow
use of corrals on BLM land north of the highway near Molas Lake. See new allotment
configurations in Figure 3-1 (addresses bighorn issues). (S-S.9)
• No bedding within ¼ mile of Little Molas Campground. (S-S.10)
• Do not use the Colorado Trail #555 as a driveway and minimize the number of times sheep
cross the trail. Keep sheep away from the trail as much as possible. (S-S.11)
Eureka Allot.
• Grazing rotations will be designed to minimize conflict with recreation use and cultural
resources, to the extent possible, in the Animas Forks townsite, especially during high traffic
times, holiday weekends, wildflower season etc. This will be accomplished by trailing around
the townsite and avoiding high-traffic times of day. (S-S.12)
Gladstone Allot
• Do not use the area south of Ohio Gulch on the west side of Cement Creek, and south of
Hancock gulch on the east side of Cement Creek (addresses mineralized soils issue). (S-S.13)
• Limit the number of days in Prospect Gulch (addresses mineralized soils issue). (S-S.14)
Maggie Allot
• Avoid salting, bedding and intentional grazing of sheep within the Uncompahgre fritillary
butterfly habitat polygon in the allotment. Trailing through the polygon will be permitted under
controlled circumstances only and must be approved in advance by the authorized officer. (S-
S.15)
Picayne/Mineral Point
• Grazing rotations will be designed to minimize conflict with recreation use and cultural
resources, to the extent possible, in the Animas Forks townsite, especially during high traffic
times, holiday weekends, wildflower season etc. This will be accomplished by trailing around
the townsite and avoiding high-traffic times of day. (S-S.16)
Red Mt Allot
• Do not use the area south of Ohio Peak (addresses mineralized soils issue). This could be
included as permit instructions or by eliminating this portion from allotment by re-drawing the
boundary. (S-S.17)
A further list of potential actions is listed in Table 2-4 (p.43). These actions could be incorporated at
any time in the future to supplement those identified as design criteria, or to accelerate the rate at
which existing conditions are moving toward the desired conditions. This list is not all-inclusive.
40

New science and management techniques may be incorporated as needed or when they are
developed. Some practices alone may not meet the desired condition, but in combination with other
practices, desired conditions may be met or moved toward. For example, a two-unit deferred
livestock grazing system alone may not provide the anticipated result, but when coupled with low
stocking rates and construction of additional water developments, desired conditions may be met.
Monitoring will occur and results evaluated by the Interdisciplinary Team and the Line Officer to
determine what adjustments are needed to ensure adequate progress toward meeting desired
conditions. Monitoring details are discussed below on p.44 of this section. The effects of all
adaptive management options will be analyzed and described in this document, or a supplemental
NEPA document and decision would be required to be prepared as appropriate.
41

Figure 2-1. Proposed Action - Avoidance Areas
42

Livestock Grazing Management Actions*
Table 2-4. Potential Adaptive Options –
Livestock Grazing Management Actions
Possible Non-Structural Actions:
Reseed with native grass, shrub and forb species (plow and seed, or broadcast seed)
Planting native shrubs
Interseed or furrow for native grass enhancement
Fertilize existing meadows to stimulate herbaceous cover
Use of integrated methods to control noxious and/or non-native plant species (including selective
herbicides, biological control agents, and mechanical methods authorized under a separate EA)
Possible Structural Actions:
Construct fence to create riparian unit – allow livestock grazing under riparian livestock grazing
guidelines
Construct fence to exclude livestock from areas of concern (riparian, streams, springs, wetlands, mesic
meadows, etc.)
Construct temporary electric fence to control livestock distribution patterns
Construct permanent fence to control livestock distribution patterns
Control livestock distribution patterns using water (turn water on or off at developed water sites)
Construct livestock water development (pipeline, tanks, windmill, sediment traps, well, stock dam,
submersible pumps, solar)
Construct water gaps to control livestock access to riparian areas
Construct armored stream crossings
Remove existing water development (pipeline, tanks, windmill, well, stock dam)
Remove existing fence line (electric, standard, permanent or temporary)
Possible Management Actions:
Adjust livestock grazing system (i.e. – rest rotation, deferred rotation, rest, high intensity/short duration.
etc.)
Adjust use of salt or supplement to draw livestock toward or away from specific areas
Incorporate a range rider to control livestock distribution (herding)
Incorporate use of herding dogs to control livestock distribution
Adjust season of use
Adjust animal numbers
Adjust number of days of livestock utilization
Rest from livestock grazing for one or more seasons
Do not allow livestock grazing
Adjust/combine allotment boundaries
Change pasture design
Implement multiple unit rotation with permittees' private land
43

Monitoring for Alternative 3
Monitoring and evaluation lead to improved management and informed management decisions.
Monitoring helps determine how the Forest Plan/RMP and NEPA decisions are being implemented,
whether AMP implementation is achieving desired outcomes, and whether assumptions made in the
planning process are valid. Monitoring and evaluation are key elements in adaptive management,
allowing the FS/BLM to measure whether or not livestock grazing management is being effective in
moving toward the desired conditions within the appropriate timeframes. Through adaptive
management, AMP’s become dynamic, relevant and useful documents.
Two types of monitoring are associated with AMP’s; implementation, or short-term, monitoring
and effectiveness, or long-term, monitoring. Implementation monitoring will measure whether or
not Forest Plan/RMP direction and desired conditions defined for this project are being met, while
effectiveness monitoring will evaluate how successful management actions are at moving towards or
achieving that direction and conditions.
Monitoring is the responsibility of both the Forest Service/BLM and the range permittee. If at any
time the results of monitoring indicate standards, guidelines, or desired resource conditions are not
being achieved as predicted, then adaptive management options will be implemented to move
towards and/or meet desired conditions. The monitoring described below is part of the Proposed
Action.
Implementation (Short-Term) Monitoring
Annual monitoring techniques will be used in a dynamic and cyclic process. As results are received
and analyzed each year, adjustments to the Annual Operating Instructions (AOI) can be made for the
following year. The AOI’s clearly explain how each allotment is to be managed on a year-to-year
basis. These instructions become part of the Term Livestock Grazing Permit for each permittee and
responsibility for carrying out the instructions falls to the permit holder. The AOI’s include
instructions for pasture rotations, numbers to be grazed, pasture on and off dates, standards for and
determination of allowable use, improvement maintenance and construction, and general allotment
operating procedures. This allows annual livestock grazing management to adapt to fluctuations in
short-term factors such as range readiness, precipitation, and other local events like fire. By allowing
these short-term adjustments to livestock grazing, Forest Plan Direction is likely to be met.
The short-term conditions will be monitored annually using a variety of methods such as:
• Rangeland Readiness: Indicators used to determine rangeland readiness are soil and vegetation
conditions. Rangeland is generally ready for livestock grazing when soil has become firm after
winter and spring precipitation, and when plants have reached the defined stage of growth at
which livestock grazing may begin under the specific management plan without long-lasting
damage. Range readiness will be evaluated on a landscape, rather than a site-specific basis. It will
be checked annually beginning a few weeks prior to the scheduled on-date and continually
evaluated until as needed until range readiness is achieved. The actual on-date is then determined
for that year.
• Allotment Inspections: Forest Service/BLM personnel make on-the-ground inspections of
utilization, livestock numbers, correct pasture use, and improvement maintenance. Results are
documented in allotment files, and corrective actions are taken as necessary.
• Allowable Use Guides: These standards are designed to ensure that short-term effects of livestock
grazing activities are able to provide for the long-term health and sustainability of rangeland
resources. There are a variety of Allowable Use Guides that may be employed on any Key Area
44

depending on the resource concerns. The most commonly used include trigger stubble height,
residual stubble height (occurring at the end of the livestock grazing season or the end of the
growing season, whichever occurs later), riparian shrub utilization, stream-bank impacts, and so
forth.
• Grazing Response Index (GRI): The GRI is used to assess the effects of annual livestock grazing
pressures, and the effects of repetitive defoliation during the growing season. Looking at GRI
scores for certain pastures or allotments over a five to ten year period provides a general indicator
as to whether or not management is providing the required combination of livestock grazing
frequency, intensity and rest opportunity to best meet physiological needs of forage resources.
• Actual Use Reports: Permittees are responsible for reporting actual use of the allotment at the end
of each livestock grazing season. When combined with analysis of other factors such as allotment
inspections, the need for annual adjustments to livestock grazing strategy can be determined.
• Use forage-use mapping and key species utilization measurements to document achievement of
Forest Plan standards and Desired Conditions for this landscape.
• Animas Forks Townsite should be annually monitored to ensure the associated design criteria is
being followed and grazing rotations are not disturbing the site. Animas Forks is currently
monitored annually by the San Juan Mountains Association’s Cultural Site Stewardship Program.
Effectiveness (Long-Term Trend) Monitoring
The most important role of monitoring is to determine whether management is successful at moving
rangeland resources towards desired conditions in an acceptable timeframe. Determining trend
toward or away from allotment objectives allows rangeland managers to accurately determine the
relative success of the management system and to adjust management to speed the accomplishment
of objectives. Trend for a variety of rangeland resource parameters may need to be monitored.
These trends tend to be long-term, and relatively slow in responding to changing conditions;
therefore, these methods will be based on analysis at five-year intervals.
The long-term health of upland resources will be monitored at upland sites on active allotments at
approximately five-year intervals using a variety of methods such as:
• Rangeland Health Matrix (RHM): This evaluation provides a general look at critical rangeland
health features on Forest Service lands. Qualitative evaluation using professional judgment of
these features can lead the examiner towards an accurate initial assessment of the rangeland and
subsequent management of that land. Comparison of future rangeland health evaluations to
initial evaluations provides a glimpse of trend in overall rangeland health. This method is
usually conducted with interdisciplinary teams.
• Standards for Public Land Health Assessment (LHA): This methodology is used for BLM land
and is similar to the RHM, in that it leads to an initial assessment of the rangeland using
qualitative professional judgment. It focuses on the five BLM Standards for Public Land Health,
and whether those standards are being met on an allotment (USDI 1997):
Standard 1 relates to uplands soils,
Standard 2 relates to riparian systems,
Standard 3 relates to plant and animal communities,
Standard 4 relates to special status, threatened and endangered species,
Standard 5 relates to water quality.
45

• Photographs and Photo-points: Photographs are extremely useful in documenting change on the
landscape. Photos need to capture the essence of the plot, point or transect, including important
characteristics and features of the site. Photos need to include enough of the horizon-line to
allow the photographer to easily repeat the photograph from the same angle at a different time.
If the above qualitative monitoring indicates that conditions are not satisfactory, or at approximately
ten-year intervals, the following types of more intensive quantitative monitoring will be performed
(or other similar methods that are endorsed by the agencies at that time):
• Cover Frequency Transects: This inventory method commonly used by the FS provides
quantitative measurements of canopy cover and frequency by plant species, ground cover, and
production by life form. It is useful when a replicated sampling design and statistical analysis is
required. It is also used to calibrate ocular estimates of canopy cover.
• Rooted-Nested Frequency Transects: This inventory method commonly used by the BLM
provides quantitative measurements of plant species composition and frequency. It also is useful
as a replicable, statistical sampling design for comparison over time.
The long-term health of riparian areas will be monitored at riparian sites on active allotments at
approximately five-year intervals using a variety of methods, such as:
• Proper Functioning Condition (PFC): This assessment process classifies riparian as being in
“Proper Functioning Condition”; “Functional-at risk”, with either an upward or downward trend;
“Non-functional”; or “Unknown.” These ratings evaluate riparian condition based in part on
presence/absence and abundance of specific vegetation and the interactions of that vegetation
with geology, hydrology, and soils.
• The line intercept method consists of horizontal linear measurements of plant intercepts along
the course of a line (tape). It is used primarily for quantitative measurements of shrub canopy
cover, and is used to calibrate ocular estimates of shrub canopy cover. This method will be used
to determine the canopy cover percent of willows needed to determine seral stages.
• Cover Frequency Transects: This inventory method provides quantitative measurements of
canopy cover and frequency by plant species, ground cover, and production by life form. It is
useful when a replicated sampling design and statistical analysis is required. It is also used to
calibrate ocular estimates of canopy cover.
• Photographs and Photo-points: Photographs are extremely useful in documenting change on the
landscape. Photos should capture the essence of the plot, point or transect, including important
characteristics and features of the site. Photos should include enough of the horizon-line to allow
the photographer to easily repeat the photograph from the same angle at a different time.
46

Alternatives Considered but Eliminated from Further Analysis
Federal agencies are required by NEPA to rigorously explore and objectively evaluate all reasonable
alternatives and to briefly discuss the reasons for eliminating any alternatives that were not
developed in detail (40 CFR 1502.14). Public comments received in response to the Proposed Action
did not suggest any entire new alternatives, but several suggestions were provided.
Some of these suggestions were outside the scope of the decision space for this project or already
decided by a higher-level decision. These included suggestions for such things as grazing fee
increases, comments regarding elk population management, and concerns with recreation
management. Because these kinds of issues are beyond the scope of the decision space for this
project, an alternative was not crafted to address them.
Many ideas were provided regarding what should be included as part of this analysis, such as
analyses of recreational impacts, watershed conditions, impacts to wildlife, monitoring plans, and
description of vegetative conditions. These kinds of items have been included in this document;
there was no need to craft an additional alternative to include them.
Other suggestions were already included in one or more of the alternatives considered in detail.
These included: suggestions to close grazing on the landscape or part of the landscape, with specific
areas to be closed often suggested (included in Alternative 1, No Action); and to leave vacant areas
vacant instead of closing them (included in Alternative 2).
Other suggestions were considered, but not included in any alternative for the reasons stated:
• Remove grazing from the Silverton Ski Area basin. The Silverton Ski Area FEIS included
acknowledgement that grazing was existing prior to the ski area permit, and will continue after
the issuance of the permit (USDI 2004).
• Prohibit grazing within a prescribed distance from the Colorado Trail and Continental Divide
Trail. This suggestion would be impractical to implement on the ground. While permittees are
encouraged to avoid the major recreation trails, it is not possible to manage sheep grazing to
such a level of precision. There are also cases where a trail follows the only logical route of
ingress or egress, which is due to the fact that many trails were originally livestock driveways
before they were used by recreationists.
• Consider management direction that is currently still in draft stages (e.g. draft Forest Plan and
draft Silverton Recreation Area Management Plan): while draft documents and guidance should
be considered, it cannot be adopted into this decision, as that would be considered predecisional.
We considered the possibility of moving domestic sheep bands from currently active allotments
where the perceived risk of contact with bighorn sheep is high to other currently vacant allotments
where the perceived risk of contact with bighorns is low. Below is a brief discussion of the possible
other allotments considered but eliminated, and the reasons for their elimination.
• Graysill and Flume allotments (FS, vacant allotments): these allotments have been vacant since
1989. They have been successfully used as a forage reserve as recently as 2002 with no adverse
impacts to vegetation and soils. There are few if any conflicts with recreation. There is a small
area of overlap with mapped summer range of the S71 West Needles bighorn sheep herd in the
extreme south end of the Flume Allotment. Due to difficult access, potential conflicts with a
summer home group, and generally steep slopes with potentially sensitive soil types, we
recommend these allotments be placed into forage reserve status. When active however, all of
the project design criteria and adaptive management practices for active allotments should be
applied to these allotments, when used. We anticipate these allotments may be used once per 15
47

years in an emergency situation, such as the Missionary Ridge fire of 2002. Restocking with a
full band of domestic sheep annually is likely to create new adverse impacts to soils and
vegetation.
• Little Molas-West Needles (BLM & FS, vacant allotment): this allotment has been in non-use for
many years and became officially vacant in 2007. We recommend the closing of this allotment
for its close proximity and large area of overlap with mapped summer range and summer
concentration areas with the S71 West Needles bighorn sheep herd. Almost the entire allotment
overlaps with mapped bighorn sheep summer range. The areas of this allotment that did not
overlap with mapped bighorn summer range were previously incorporated into the currently
active Engine Creek/Deer Creek allotment. If this allotment were to be restocked with domestic
sheep, potential for contact with bighorn sheep appears to be high.
• West Lime (FS, vacant allotment): The West Lime allotment has been in non-use for many years
and became officially vacant in 2007. While this allotment has sufficient capacity and is in good
ecological condition, bighorn rams have recently expanded into western portions of this
allotment during summer, overlapping with the domestic sheep grazing season. High recreation
activity in the entire South Mineral Creek drainage makes domestic sheep ingress and egress to
this allotment difficult and highly contentious. Several modifications to the boundaries of this
allotment were proposed to remove areas of potential bighorn sheep overlap and avoid high use
recreation areas. However, all reasonable options for boundary adjustments left insufficient
capacity remaining to sustain a band of domestic sheep for a viable grazing season without
creating adverse impacts to soils and vegetation, and likely conflicts with popular recreation use
areas.
• Minnie Gulch (BLM, vacant allotment): The Minnie Gulch allotment is believed to have been
vacant since 1983, although incidental use has occurred occasionally. This allotment is managed
in conjunction with the Cottonwood allotment administered by the Gunnison Ranger District of
the Gunnison National Forest. Almost the entire allotment overlaps with mapped bighorn sheep
summer range. If this allotment were to be restocked with domestic sheep, potential for contact
with bighorn sheep appears to be high. We recommend the closing of this allotment for its close
proximity and large area of overlap with mapped summer range of the Pole Mountain/Upper
Lake Fork bighorn sheep herd (S33).
• Needles Mountains (FS, vacant allotment): No records are available for this area while it was an
active allotment. Very little suitable domestic sheep range exists in the allotment due to generally
steep and rugged mountainous terrain. In addition, there are very limited access routes into the
allotment. There is a large area of overlap with mapped summer range, summer concentration,
and winter range areas with the S71 West Needles bighorn sheep herd. If this allotment were to
be restocked with domestic sheep, potential for contact with bighorn sheep appears to be high.
For this reason, we recommend closing this allotment.
• Pine River Allotment (FS, vacant allotment): This is a large vacant allotment that includes much
of the headwaters of the Pine River in the central Weminuche Wilderness. There is substantial
summer recreation in the Granite Lake, Snowslide Canyon, Rincon La Vaca, and Rincon La Osa
portions of this allotment, and the Continental Divide Trail parallels the boundary of this
allotment for a number of miles. This allotment has been vacant since the early 1980’s.
There is substantial overlap between the Pine River Allotment and mapped summer range of the
S16 Cimmarona/Hossick bighorn sheep herd, including all of Snowslide Canyon. Mapped
bighorn summer range for S16 extends from the headwaters of the Piedra River drainage west to
the Pine River at the mouth of Rincon La Osa, making domestic sheep access to or from the Pine
48

River very difficult without passing through mapped bighorn sheep summer range. In addition,
the Rincon La Osa portion of the Pine River Allotment is within 1 to 2 air miles of mapped
summer range of the S28 Vallecito Creek bighorn sheep herd.
Historic livestock ingress/egress to the Pine River Allotment was from the south along the Pine-
Piedra Stock Driveway, or along the Pine River Trail from Vallecito Reservoir. Both of these
routes pass through the heart of the S28 Vallecito Creek bighorn sheep herd’s summer range and
summer concentration area. The Pine River Trail is an extremely popular summer recreation trail
and is the main access route for hikers and horseback riders into the central Weminuche
Wilderness and the Pine River basin. Re-opening the Pine-Piedra Stock Driveway for use by
sheep would require a significant amount of mechanical work, including moving large amounts
of downed logs that were placed across the trail as fireline mitigation after the 2002 Missionary
Ridge wildfire.
To prevent having to trail domestic sheep up the Pine River trail and through the heart of the S28
Vallecito Creek bighorn sheep herd’s summer range and summer concentration area, or up the
lengthy Pine Piedra Stock Driveway, it was proposed to access the Pine River Allotment from
the north via Rio Grande Reservoir. The proposal was to truck domestic sheep to Rio Grande
Reservoir, then trail sheep up the Weminuche Trail, south over Weminuche Pass, and into
Rincon La Vaca and Rincon La Osa. Sheep would then be trailed back out via the Pine River
Trail, over Weminuche Pass and back down to Rio Grande Reservoir. We were unable to obtain
permission from the Rio Grande National Forest to use this access route. This route would take
sheep through and very close to mapped summer range for the S16 Cimmarona/Hossick herd.
If the Pine River Allotment were to be restocked with domestic sheep, potential for contact with
bighorn sheep from the S16 Cimmarona/Hossick herd and the S28 Vallecito Creek herd appears
to be high. Moving domestic sheep from a “High Risk” allotment in the Silverton Landscape to
the upper Pine River Allotment would be moving sheep to an area of equal or greater risk for
contact with bighorn sheep, thereby maintaining the same problem, just moving it to a different
location. We recommend not stocking any portion of the Pine River Allotment due to its lengthy
wilderness access route, lack of permission for access from Rio Grande Reservoir, substantial
overlap with mapped summer range for the S16 Cimmarona/Hossick bighorn sheep herd, and
need to trail through mapped summer range of the S28 Vallecito Creek bighorn sheep herd.
• Fall Creek, Johnson Creek, Leviathan, Rock Creek, Cave Basin, and Flint Creek (FS, vacant
allotments): These six allotments are all outside the Silverton Landscape. They have all been
vacant for many years. They were vacated largely due to their location in remote areas of the
Weminuche Wilderness with difficult access, and their relatively small size for a sustainable
season of grazing. All of these allotments would have a high potential for contact with bighorn
sheep, either by overlap with or close proximity to mapped bighorn summer range of the S28
Vallecito Creek bighorn sheep herd, or by overlap or close proximity with their associated stock
driveways necessary for ingress/egress of domestic sheep bands. There have been few requests
from the domestic sheep industry to use these remote areas. There is a slight possibility that if
several of these allotments were combined, a logical grazing unit could be developed and
managed effectively. However, the high potential for contact with the S28 bighorn herd would
likely remain and would be difficult to mitigate. Moving domestic sheep from the Silverton
Landscape to any one or combination of these six allotments would be moving sheep to an area
of equal or greater risk for contact with bighorn sheep. For these reasons we recommend these
six allotments not be considered for restocking with domestic sheep from active allotments in the
Silverton Landscape.
49

Comparison of Alternatives ________________________
This section provides a summary of the effects of implementing each alternative. Information in the
table is focused on activities and effects where different levels of effects or outputs can be
distinguished quantitatively or qualitatively among alternatives.
Issues
Water Impacts
Vegetation/Soil
Impacts
Recreation Impacts
Wildlife Impacts
Socio-Economic
Impacts
Cultural Resource
Impacts
Table 2-5. Comparison of Alternatives Based on Significant Issues
Indicator for
Comparison
Acres Open to
Grazing with
Mineralized Soil
Riparian
Monitoring
Alternative 1
No Grazing
Alternative 2
Current
Management
0 acres 1441 acres
None for
grazing
purposes
Infrequent PFC
Alternative 3
Adaptive
Management
169 acres
PFC at ~5 yr.
intervals
Design Criteria None No Design Criteria Avoid mineralized
soils,
Design Criteria to
reduce water impacts
Acres Open for
Grazing (Total in
Allotments)
Upland
Monitoring
0 acres 191,600 acres (active
or vacant allots):
8 active,
6 vacant,
1 previously closed
None for
grazing
purposes
99,100 acres (active
or vacant allots):
8 active,
2 forage reserve,
4 newly closed.
1 previously closed
Infrequent monitoring RHM & LHA at ~5
yr. intervals;
Cover Freq. or
Rooted-Nested at ~
Design Criteria None
10 yr. intervals
Design Criteria to
reduce veg impacts
Monitoring None for
grazing
purposes
Informal monitoring Establish Photopoints
Design Criteria None Avoid Animas Forks Avoid Animas Forks;
Avoid CT and CDT;
Other Design Criteria
to reduce conflicts
Design Criteria None None Bighorn Design
Criteria (Table 2-2);
UFB avoidance area
Acres Open to 0 acres 41,400 acres overlap 6,000 acres overlap
Grazing in
(in active or vacant (in active or vacant
Bighorn Range
allots)
allots)
Acres of UFB
avoidance area
0 acres 0 acres 70 acres
Qualitative Five ranching No change Increased costs of
Description families out of
grazing
business
implementation and
administration
Design Criteria None None Design Criteria to
reduce cultural
impacts
50

CHAPTER 3 - AFFECTED ENVIRONMENT AND
ENVIRONMENTAL CONSEQUENCES
Council on Environmental Quality regulations direct agencies to succinctly describe the environment
that may be affected by the alternatives under consideration (40 CFR 1502.15). As such, this chapter
summarizes the physical, biological, social, and economic environments of the project area and the
effects of implementing each alternative on that environment. It also presents the scientific and
analytical basis for the comparison of alternatives presented in Table 2-3 (p.50).
The following chapter is organized by resource area to address issues that were raised during
scoping (e.g. Vegetation, Recreation, and Watershed). Resources for which there are no issues are
not discussed (e.g. Air Quality).Each resource section begins with a description of the Affected
Environment, or the existing conditions. Then, each section provides an analysis of direct and
indirect effects, or Environmental Consequences, of implementing each alternative. Direct effects
are caused by the action and occur at the same time and place. Indirect effects are caused by the
action and occur later in time or are removed in distance. Differences in impacts between
alternatives are emphasized. Each resource section then describes Cumulative Effects, which are the
direct and indirect effects of the project added to the effects from other past, present, and reasonably
foreseeable actions.
There are no designated Wild and Scenic Rivers, prime farmlands, or parklands in the project area;
therefore, there will no impacts to these resources from any of the alternatives, and these resources
are not discussed further.
One element of the proposed action that is not discussed further in this document is the impact of
using the Graysill and Flume Allotments as a forage reserve. Forage Reserve allotments are grazing
areas, that for a variety of factors are not suitable for sustained annual grazing, but are capable of
being used occasionally. The Graysill Allotment has been vacant since 1966 and the Flume
Allotment since 1983. The allotments have been vacant due to a number of factors, such as high
predator losses, extremely steep terrain, and limited access. While they are not appropriate for use as
full-time active allotments; they are lands that could be grazed occasionally. Events such as fire or
localized drought may result in the need for alternate pasture for permitted livestock from other
allotments. Without alternate pasture available, permittees would often have no other choice than to
sell their livestock. Having available emergency pasture would allow the FS/BLM to work with
permittees to potentially prevent major economic hardship during such events. At such time as a
forage reserve allotment is proposed for use, the Forest Service would require it to be used under
Design Criteria, Desired Conditions, and utilization guidelines as for similar nearby active
allotments. Because this use would occur only occasionally, and because it would be held to similar
standards as elsewhere, impacts from emergency usage of the Graysill and Flume Allotments would
be similar to, or less than, impacts on the described active allotments, and are not described at length
in this document.
Finally, although the Silverton Watershed Allotment is included within the analysis area boundary
for this landscape, it is not included in the following analyses because the allotment has already been
closed to grazing and is not being re-considered for opening. The allotment was closed in order to
protect the watershed upslope of the Town of Silverton’s domestic water intake, and this is still a
valid reason for closure.
51

Water Quality ___________________________________
AFFECTED ENVIRONMENT
The analysis area generally encompasses the Animas River watershed above the confluence of
Cascade Creek and the Animas River, with the Graysill allotment and portions of the Flume
Allotment in the Hermosa watershed. Precipitation ranges from 25 to 50 inches, and streamflows
are highest in the spring when the showpack melts. Summertime thundershowers are common.
In the southern third of the analysis area, water quality is good, and stream patterns are typically
dendritic. The following allotments are in this category: Graysill, Flume, Engine Creek/Deer Creek,
Little Molas/West Needles, and the Forest Service portion of the Elk Creek allotment.
The northern two thirds of the analysis area (and the remaining allotments) are influenced by the
Silverton Caldera, an area where hydrothermal alteration associated with up-welling lava created
zones of metallic ore deposition and surrounding acidic rocks. Stream patterns tend to follow the
ring faults and radial faults associated with the subsidence of the caldera (Cement Creek and the
Animas above Silverton follow ring fractures. Maggie Gulch follows a radial fracture). Water
quality within the caldera is naturally acidic, with concentrations of metals such as iron, manganese,
copper zinc and aluminum at levels that are toxic to fish in many areas. Gold and silver mining
starting in the late 1800’s has increased the metal load in the streams through acid mine drainage and
leaching from waste rock and tailings. Increased metals in streamside sediments from early 1900’s
ore milling can be traced the full length of the Animas to its confluence with the San Juan River in
New Mexico. The Animas River Stakeholders Group, after extensive testing and analysis, proposed
water quality standards based on remediation of the worst polluting mine sites. These were
presented in the Use Attainability Analysis for the Animas River Watershed (Simon, 2001). These
standards were incorporated by the State in the Total Mean Daily Load allocation and the water
quality standards for the affected streams. Mine reclamation in the last 15 years has benefitted the
water quality and fishery of the Animas. A substantial amount of the metal load comes from natural
background and from undifferentiated man-made sources. These undifferentiated sources include
hillslope erosion that can be increased by grazing.
The town of Silverton draws municipal water from Boulder Gulch and Bear Creek. Neither of these
is permitted for sheep grazing.
An inventory was conducted by BLM in 1998 and 2001 of wetlands and riparian areas. A total of 91
sites, covering all major drainages were inventoried for Lentic Proper Functioning Condition
(Prichard, 1999, TR 1737-16). The Lentic PFC protocol addresses age class and composition of
riparian/wetland vegetation. Typically sheep do not spend much time in wetlands, so this factor may
not be a strong indicator of sheep grazing impacts. The protocol also assesses such things as
whether the upland watershed contributes to riparian degradation, whether hydrology has been
disrupted (such as by trails or hoof action), and whether there is excessive erosion or sediment
deposition. These factors would tend to integrate any impacts from grazing on dry upland hillslopes,
as well as grazing in the wetland, so are indicators of grazing impacts in the watershed. About 94%
of the sites inventoried were at Proper Functioning Condition. The five sites that were rated
“functional at risk” were because of roads and mining. Twelve sites were in watersheds where sheep
were noted as being present, and all those riparian areas rated at PFC. One site that was rated
“functional at risk” noted sheep grazing in the past, but grazing was not mentioned as causing the
erosion that placed the riparian area at risk.
Grazing of sheep or cattle have been shown to increase fecal coliform bacteria in streams (Gary,
1985). A study for San Juan County on sensitivity of different lands for development determined
52

that sheep grazing was a potential landscape disturbance because of nitrate loading from sheep
manure (Raby, 2005). Bacteria were not tested in this study, but sheep droppings would be a source
of both nitrate and coliform bacteria. Sites tested by Raby in allotments in this analysis were
Prospect Gulch (Gladstone Allotment), Deer Park Creek (Deer Park Allotment), Cunningham Creek
and Maggie Gulch (Maggie Allotment). High nitrates were observed in Arrastra Gulch (which is
not grazed), a talus location in Cunningham Creek (no grazing would happen in the talus) and Deer
Park Creek, which is grazed. No correlation of sheep locations at the time of sampling was
provided. It does not appear from this data that sheep grazing has any consistent impact on nitrates
in water in San Juan County. Since sheep droppings would be a source of both nitrate and fecal
coliform, and since there were no degraded riparian areas indicating concentrations of sheep near
water sources (see below), we conclude that the risk is low for fecal coliform from sheep being a
contaminant in these watersheds. Since the likelihood is low, we have not proposed any monitoring
of fecal coliform and will rely on implementation of BMPs and monitoring of riparian areas to
mitigate this potential contaminant (USDA 2006).
The FS/BLM did extensive field work and monitoring in the analysis area in 2008. General
observations were that sheep did not congregate on stream banks or in wet areas. In particular, the
Ophir Fen was avoided by sheep that moved through the vicinity shortly before the observation, so
there was no impact to this important wetland resource. Stream Proper Functioning Condition
assessments (and others done in 2004) showed all streams monitored to be at PFC. Stream banks
that were observed soon after sheep had utilized the area (Horseshoe Creek and Velocity Basin)
showed no bank trampling and minimal browsing on streamside plants.
In most locations, trails from sheep movement were visible as bent-over plants, but no bare soil was
exposed, no erosion is taking place, and impacts were very temporary. In areas where soils are thin
and vegetation is sparse, historic sheep grazing has left a visible network of trails and terraces.
Current sheep use has likely inhibited the naturally slow revegetation of these trails, but is not
causing erosion on existing trails, nor an increase in the number of trails. An exception to this was
the area between Spencer Basin and Highland Mary Lakes, where current sheep use has exposed
additional areas of bare soil. There were numerous instances in most allotments where recreation
trails for hikers and horses had exposed soils and had eroded. Where these trails were trenched,
parallel trails have developed, and some deliver sediment directly to the streams. Frequently, sheep
have also used these same trails, and distinguishing between recreation and sheep impacts is not
easily possible.
Compliance with Clean Water Act
The Clean Water Act recognizes Best Management Practices as the primary mechanism to control
nonpoint sources, as supported in EPA guidance (EPA 1987), “For proposed management actions,
Best Management Practices designed and implemented in accordance with State approved process
will normally constitute compliance with the Clean Water Act.”
FSH 2209.13-93.3 states, “Compliance with the Clean Water Act is achieved through the proper
site-specific design, implementation and monitoring of Best Management Practices,” and, “As long
as Best Management Practices have been applied and monitoring and adjustments are ongoing, then
the Forest Service is in compliance with the Clean Water Act.”
The Watershed Conservation Practices Handbook (FSH 2509.25) also states that, “Watershed
conservation practices will meet applicable Federal and State laws and regulations, including State
Best Management Practices.”
Design criteria and monitoring for each alternative are described earlier in this document.
53

ENVIRONMENTAL CONSEQUENCES
Alternative 1
Under this alternative, the visible trails from the high number of sheep grazed in the early 1900’s
would eventually revegetate, though it would be very slow, and use from deer and elk would hinder
this revegetation. This would reduce soil movement from uplands into streams.
Under this alternative any contribution of nitrate or fecal coliform from sheep manure would be
discontinued, though the existence or amount of any current impacts is unknown.
Under this alternative, heavy metals contributed to streams from sheep grazing on mineralized soils
would be eliminated. It is likely that extensive sheep grazing in the past has decreased the vegetative
ground cover in mineralized areas and accelerated erosion and exposure of oxygen and water to
metal sulfide bearing substrates. This weathering and erosion of metal-bearing rock and soil is a
portion of the undifferentiated background metal load documented in the Use Attainability Analysis
(Simon, 2001). Under a “no grazing” alternative, whatever portion is attributable to grazing would be
eliminated.
Alternative 2
Under this alternative, natural revegetation of historic sheep trails would continue, but at a slower
rate than in Alternative 1. Sheep use on historic trails likely keeps them from recovering as quickly
as they would if there were no sheep.
The existence or amount of nitrate or fecal coliform from sheep grazing is currently unknown,
though it would continue at a similar amount with the continuation of current grazing
Continued contribution of metals in streams from grazing on mineralized areas may continue.
About 119 acres on the Gladstone allotment and 687 acres on the Red Mountain allotment are in
areas suitable for sheep grazing overlapping with highly mineralized areas (Bove, 2007).
Additionally, 635 acres of the West Lime allotment overlap with mineralized areas and would remain
available for possible future re-stocking, for a total, of approximately 1,441 acres of overlap. In the
past, most of these areas were grazed, though recently not as much use has been made of the
mineralized areas.
Alternative 3
Under this alternative, natural revegetation of historic sheep trails would continue, at a slower rate
than in Alternative 1, but a faster rate than in Alternative 2. . The heavily used area and new trails
between Spencer Basin and Highland Mary Lakes would be improved because of the actions
specified for the Deer Park Allotment.
Any impacts from nitrates or fecal coliform would be similar to Alternative 2, because there is no
need for particular actions to address these constituents.
Under this alternative, impacts of grazing on mineralized soils would be reduced almost to the level
of Alternative 1. The proposed action of “excluding grazing south of Ohio Peak on the Red
Mountain allotment and excluding grazing south of Ohio Gulch west of Cement Creek and south of
Hancock Gulch east of Cement Creek on the Gladstone allotment” significantly reduces the acreage
of mineralized soil available for grazing. This reduces the amount of mineralized soil likely to be
grazed in the Red Mountain allotment from 687 to 93 (an 86% reduction) This also reduces the
amount of mineralized soil likely to be grazed in the Gladstone allotment from 119 to 76 (a 36%
reduction). Since the West Lime Allotment would be closed, this removes an additional 635 acres of
mineralized soil in suitable grazing from areas that have been grazed at some time in the past, for a
total of approximately 169 acres of overlap. The proposed action in this document removes a total
54

of 1,272 acres of mineralized soil from grazing. The largest amount of mineralized still likely to be
grazed are in Prospect Gulch, and the proposed action intends to limit the number of days sheep are
allowed in Prospect Gulch. Compared to the mineral soil exposed to erosion from historic mining
activities, any small increase due to sheep grazing is expected to be minimal. Gladstone Allotment
was observed during rainstorms in 2008, and found that trailing and grazing from sheep that day and
the previous day was producing no sediment-laden runoff, but water in roadside ditches below mine
dumps was carrying significant sediment load.
CUMULATIVE IMPACTS
The largest impact to watersheds and water quality in this analysis area is past mining, milling and
road building. This is described under the affected environment (above). Other activities that can
negatively impact watersheds and water quality include: private land development (mining, summer
homes, ski area, etc.), new road construction, road and trail use, road maintenance, and recreational
pack stock use.
Past and ongoing mine reclamation projects undertaken by members of the Animas River
Stakeholders Group are a beneficial impact to water quality. The impact from domestic sheep
grazing under Alternative 3 (adaptive management) is expected to be inconsequential in the context
of cumulative effects.
Vegetation & Soils________________________________
AFFECTED ENVIRONMENT
The Silverton project area occurs in a mountainous landscape dominated by alpine vegetation and
spruce-fir forests. Mixed conifer forests, aspen forests, and mountain grasslands also occur to a
limited extent, and riparian areas and wetlands are scattered throughout the area. Most of the project
area is associated with volcanic deposits of volcaniclastic and near-source facies, volcanic deposits
of the Henson and Burns geologic formation, and sedimentary deposits of the Cutler, Rico, Hermosa,
and Molas geologic formations.
This section focuses on the vegetation and soils of the alpine zone (the alpine major vegetation type)
within the project area, since this is the area most affected by sheep grazing. Vegetation and soils of
the other vegetation types of the project area display no effects or only minor adverse effects from
sheep grazing.
The alpine zone on San Juan Public Lands occurs at elevations above about 11,500 feet where the
growing season is short, the winters are long, the winds are high, and the sun is intense. The alpine
landscape was shaped by geologic events and glaciation, and is both steep and rugged, and gentle
and smooth. Rock outcrop and talus slopes are common. Soils are shallow and rocky on steep slopes
and exposed ridges, and deeper, less rocky, and more productive on other sites. There is tremendous
diversity of species and vegetation types within the alpine zone and plant communities often change
quickly and abruptly over short distances, due to small-scale topographic changes that exert a
significant influence on snow and moisture conditions and the associated vegetation.
Alpine rangelands have been used for sheep grazing since the mid 1800s. Prior to government
control, sheep were herded in tightly grouped bands and usually bedded in the same location for
several nights in a row, which resulted in large forage losses and in soil damage (Paulsen 1960).
Some sites in the project area still display these historic effects (ID team observation 2008).
Currently sheep (including the ones in the project area) are herded loosely but will aggregate in large
groups when resting or drinking and then gradually split up into smaller groups as they graze away
55

from water or bedgrounds (Arnold and Dudzinski 1978). Sheep are considered “intermediate
feeders” meaning they utilize graminoids, forbs, and shrubs and have the ability to adjust their
feeding habits to whatever is available, but they generally prefer forbs (Vallentine 1990, Johnson
1962, Paulsen 1960). Leaves are the most readily grazed portions of most plants with sheep
averaging 40% utilization of leaves compared to 9% for stems (Cook et al. 1948). Sheep
consumption and trampling of the flowers of plants may affect seed production and may reduce the
amount of flowers available for wildflower viewing, but in most cases will not cause mortality to the
affected plants.
Vegetation Types
Alpine vegetation types at the subclass level include fellfield, turf, upland willow, dwarf willow,
wetland willow, herbaceous wetland, and krummholtz (Baker 1983, Paulsen 1960, Dick-Peddie
1993, Thilenius 1975). Currently most of these types display high native species diversity, adequate
ground cover, and productive soils. Some sites reflect effects associated with long-term domestic
sheep grazing including sheep trailing along livestock driveways and across mountain slopes, and
trampling at sheep bedgrounds.
The fellfield type is an upland type that occurs on harsh, wind-swept sites with shallow, rocky,
moderately well to well-drained soils that classify predominantly as Lithic Dystrochrepts, loamyskeletal
(Pannell 2006, Redders personal observation 2008). Surface rock (gravel and cobble) and
patches of bare soil are common. It is dominated by short cushion plants (forbs) and displays a
relatively low canopy cover. In this project area, the fellfield type commonly occurs as small patches
mixed within the matrix of the alpine avens (Acomastylis rossi) turf type. Common species of the
fellfield type include Silene acaulis, Paronychia pulvinata, Erigeron vagus, Amerosedum
lanceolatum, Ivesia gordonii, Trifolium nanum, Lidia obtusiloba, and Phlox condensata. Sheep
foraging in this type is minor as the dominant plants that occur there are not preferred forage species.
Current species composition and distribution in this type are likely similar to conditions found
during the reference period. Effects from sheep trailing and trampling (soil displacement and sheet
erosion) however can be significant in the fragile soils of this vegetation type.
The dwarf willow type is an upland type that is dominated by both snow willow and alpine willow
(Salix nivales and Salix petrophila) small, prostrate-growing plants that occur in separate or mixed
patches. The type occurs on relatively dry sites on moderately well to well-drained, often shallow
soils. Soils classify predominantly as Lithic Dystrochrepts, loamy-skeletal (Pannell 2006, Redders
personal observation 2008). Phlox condensata, Amerosedum lanceolatum, Acomastylis rossi and
lichens are common associates in the dwarf willow vegetation type. Sheep foraging in the dwarf
willow type is minor as the dominant plants that occur there are not preferred forage species. Current
species composition and distribution in this type are likely similar to conditions found during the
reference period.
The turf type is an upland type that occurs on protected sites away from excessive wind and tends to
have relatively deep (greater than 20 inches to bedrock), moist, moderately well to somewhat poorlydrained,
and well-developed soils that classify predominantly as Typic Dystrochrepts, loamy-skeletal
(Pannell 2006, Redders personal observation 2008). It is dominated by forbs and graminoids, and
usually displays a relatively high canopy cover. Within the turf type of this project area a number of
plant community types are present including a Kobresia myosuroides type that occurs on relatively
dry sites, a Parry rush (Juncus parryi) type, and an alpine avens (Acomastylis rossi) type, the latter
being the most common. The alpine avens type, where alpine avens is the dominant or codominant
species, is quite variable ranging from a moist phase where Caltha leptosepala is common to a dry
phase where cushion plants are common. On less productive sites and sites where natural erosion is
occurring, which is common in alpine areas including those of this project area, the turf types display
56

a more open canopy cover, less species diversity and abundance, and more bare soil. In addition to
the species mentioned above, other common species in the turf type include Bistorta bistortoides,
Bistorta vivipara, Agoseris aurantiaca, Allium geyeri, Arnica mollis, Carex microptera, Castilleja
haydenii, Castilleja occidentalis, Clementsia rhodantha, Deschampsia cespitosa, Dugaldia hoopesii,
Elymus glaucus, Elymus trachycaulus, Erigeron coulteri, Erigeron simplex, Festuca brachyphylla
ssp. coloradensis, Ligularia amplectens, Micranthes rhomboidea, Oreoxis bakeri, Phleum
commutatum, Poa arctica, Polemonium viscosum, Potentilla subjuga, Rydbergia grandiflora,
Sibbaldia procumbens, Solidago simplex var. nana, and Trisetum spicatum ssp. congdonii. Small
patches or individuals of Salix planifolia and Salix brachycarpa also occur within this type. The
abundance and distribution of these species within a particular alpine avens plant community is
highly variable dependant on site characteristics as described above and on the degree of historic and
current sheep utilization. Sites that have experienced heavy long-term sheep grazing display less
diversity of forage species, particularly forbs.
Sheep foraging is heavy in the alpine avens type of this project area as many of the common plants
in that type are preferred sheep forage species including Agoseris aurantiaca, Allium geyeri,
Deschampsia cespitosa, Erigeron coulteri, Erigeron simplex, Ligularia amplectens, Sibbaldia
procumbens, Solidago simplex var. nana, and Caltha leptosepala (Johnson 1962, Paulsen 1960,
Redders 2008). Alpine avens is not readily used until the fall following a hard frost (Paulsen 1960).
Sheep trailing and trampling, which cause soil displacement and sheet erosion in this type are
evident in some places, but they are minor in most of this type due to the high density and canopy
cover of plants that protect the soils from hoof action. Most sheep trails are likely remnants of those
created in the distant past when sheep numbers and grazing intensity were high.
Sheep bedgrounds commonly occur in the alpine avens vegetation type which results in sheep
spending significant amounts of time there including multiple days in succession, year after year. In
some places within this project area, this has resulted in overgrazing and trampling leading to a
decrease in the diversity and abundance of forbs, reduced forb vigor, and increased sheet erosion.
Riparian areas and wetlands are abundant in the alpine zone of the project area occurring on lowlying
sites with poorly to very-poorly-drained soils that classify predominantly as Cryaquolls,
Cryaquents, and Cryofibrists (Pannell 2006, Redders personal observation 2008). They display high
diversity and high canopy cover of hydrophytic plants and are in mid to late-seral stages (Redders
personnel observations, 2007 and 2008). The wetland willow type occurs on streambanks and in
adjacent floodplains and includes Salix planifolia/Salix brachycarpa, Salix planifolia/Carex
aquatilis, Salix planifolia/Caltha leptosepala, and Salix brachycarpa/Mesic forbs plant communities
(Redders 2003). The herbaceous wetland type occurs along stream channels and in adjacent
floodplains and includes Caltha leptosepala, Caltha leptosepala/Carex aquatilis, Carex aquatilis,
Calamagrostis canadensis, and Cardamine cordifolia/ Mertensia ciliata/Senecio triangularis plant
communities (Redders 2003). In addition to the species mentioned above, other common herbaceous
species in the general riparian-wetland type include Pedicularis groenlandica, Rhodiola integrifolia,
Clementsia rhodantha, Primula parryi, Deschampsia cespitosa, Canada reedgrass, Drummond rush,
and water sedge. Eriophorum altaicum, a rare species, is also common in the Caltha leptosepala and
Carex aquatilis types. Sheep browsing on both Salix planifolia and Salix brachycarpa is moderate to
heavy in some places (ID team observation 2008) and sheep readily forage on Caltha leptosepala
and Carex aquatilis (Redders personal observation 2008).
The upland willow type found on mountain sideslopes is associated with springs or sites that provide
an abundance of moisture throughout the year. It is dominated by Salix planifolia and/or Salix
brachycarpa and usually displays high density and canopy cover of willows. Soils classify
predominantly as Typic Dystrochrepts, loamy-skeletal (Pannell 2006, Redders personal observation
57

2008). It differs from the wetland willow type by its better-drained soils and its upland landscape
position. Sheep readily browse on both of the willows of this type (ID team observation 2008), but
Salix planifolia seems to be preferred. Most willow plants and plant communities are vigorous, but
some heavy browsing is occurring in some places as reflected in hedged plants. Some sheep trailing
is also evident in this vegetation type. Current species composition and distribution in this type are
likely similar to conditions found during the reference period.
Krummholz, which is an upland type dominated by dwarfed conifers (mostly Picea engelmannii)
and herbaceous species, is a transition type that occurs between spruce-fir forests of the subalpine
climate zone and the treeless alpine zone. Sheep foraging in this type is relatively minor. Current
species composition and distribution in this type are likely similar to conditions found during the
reference period.
The spruce-fir forest type is an upland type dominated by Engelmann spruce and subalpine fir trees
and generally displays high tree densities and closed canopy covers, which limit forage production.
Within the project area, this type has been mostly unaffected by sheep grazing.
Threatened, Endangered, or Proposed Plant Species
There are no plant species federally listed as threatened, endangered, or proposed under the
Endangered Species Act known to occur on the San Juan Public Lands or within this Project Area.
Sensitive Plant Species
There are nineteen R2 Regional Forester’s sensitive species that occur on the Forest Service lands
within the San Juan Public Lands and six others that have the potential to occur there; and eight
BLM sensitive species that occur on the BLM lands within the San Juan Public Lands and one other
that has the potential to occur there. Most of them were removed from further analysis because there
are no known occurrences of those species within or near the project area, because it is highly
unlikely that they would be in the project area, or because the project area did not contain potential
habitat for them. Five sensitive plant species (Eriophorum altaicum var. neogaeum, Parnassia
kotzebuei, Machaeranthera coloradoensis, Cryptogramma stelleri, and Carex viridula were
evaluated in detail because they are known to occur in this project area, and three others
(Eriophorum chamissonis, Eriophorum gracile, and Gilia sedifolia) were evaluated in detail because
the project area contains potential habitat for them. Detailed descriptions and analysis of these
species can be found in the Biological Evaluation for Plants in the project record.
Noxious Weeds
Noxious weeds are the invasive or non-native species that are generally considered the worst
because of their negative impacts on native ecosystems, and are defined by the State of Colorado
(C.R.S. 1990). The most common noxious weeds within the Silverton landscape area are Yellow
toadflax and Canada thistle. Since 2002, noxious weed treatment has been concentrated along the
main travel corridors, including BLM Roads, some abandoned mining roads and sites, some system
trails, and dispersed camping areas. Control of weed populations has been relatively successful in
areas where treatment has occurred in the past years. Much of the project area is remote and
inaccessible by vehicles. Noxious weeds, especially yellow toadflax are continuing to spread but
are largely confined to motorized travel corridors. Biological control insects could be the most
efficient way to treat remote areas. The following summaries describe challenges unique to
specified grazing allotments within the project area.
Engine Creek/Deer Creek Allotment
Noxious weeds are not an issue on this allotment. There is some Canada thistle in the Engine Creek
and Deer Creek drainages. There is occasionally some musk thistle in the US Hwy 550 right of way.
58

Deer Park Allotment
Noxious weed treatment on the Deer Park Allotment is concentrated along the roads and system
trails. Yellow toadflax, Canada thistle and Oxe Eye Daisy occur in Kendall Gulch, Deer Park Creek,
Silverton railroad right of way, and Cunningham Gulch. These areas were spreading but containment
is hopeful.
Elk Creek Allotment
Noxious weed treatment in this area has been concentrated along the roads. Yellow toadflax occurs
in isolated patches along the Stony Pass road, with scatterings of Canada thistle occurring at
dispersed campsites along roads.
Eureka/California Gulch Allotment
Noxious weeds are not an issue on this allotment. There is some Canada thistle along the Eureka
Gulch road.
Flume and Graysill Allotments
Noxious weeds are not an issue on these allotments. There is some Canada thistle along the Bolam
Pass road.
Gladstone Allotment
Noxious weed treatment on the Gladstone Allotment is concentrated along the Cement Creek road
and old mining roads. Yellow toadflax, Canada thistle and Oxe Eye Daisy occur in much of the area
along Cement Creek road. These areas were spreading but containment is hopeful.
Little Molas/West Needles Allotment
Oxe Eye Daisy occurs on Little Molas/West Needles Allotment in the Andrews Lake vicinity.
Yellow toadflax occurs at several sites along the Old Lime Creek road. Treatment is on going and
containment is expected.
Maggie Gulch Allotment
Noxious weed treatment in this area has been concentrated along the roads. Yellow toadflax occurs
in isolated patches along the Stony Pass road, with scatterings of Canada thistle occurring at
dispersed campsites along roads.
Minnie Gulch Allotment
Canada thistle is along the old mining road within the Minnie allotment but are remaining confined
to disturbed sites. Treatment is on going as Canada thistle is difficult to control.
Needles Mountains Area
Canada thistle is present along Needle Creek and the Silverton railroad right of way. Treatment is
on going as Canada thistle is difficult to control.
Picayne/Mineral Point Allotment
Canada thistle is along the Picayne Gulch road and the Animas Forks road but generally remains
confined to disturbed sites. Treatment is on going as Canada thistle is difficult to control.
59

Red Mountain Allotment
Yellow toadflax occurs in the vicinity of the substation along Mineral Creek. Treatment is ongoing
and eradication of this site is expected.
West Lime Allotment
Noxious weed treatment in this area has been concentrated along the roads. Yellow toadflax occurs
in isolated patches along the South Mineral and Clear Lake roads, with scatterings of Canada thistle
occurring at dispersed campsites along roads. Treatment will continue to occur for many years
before containment is expected.
Summary Of Noxious Weeds Conditions
Noxious weed will continue to be a problem in this landscape. Treatment will continue to be
concentrated along travel corridors and other areas accessible by spray equipment. Biological
control using insects will not be utilized over much of the landscape in that patches of sufficient size
and density due not exist to support the insects. However, as situations evolve where insects will be
appropriate that may be used. It is unlikely that noxious weeds will be eradicated, but instead,
managed to an acceptable level over time.
ENVIRONMENTAL CONSEQUENCES
This section focuses on the vegetation and soils of the alpine zone (the alpine major vegetation type)
within the project area, since this is the area most affected by sheep grazing. Vegetation and soils of
the other vegetation types of the project area display no effects or only minor adverse effects from
sheep grazing.
Alternative 1 –No Action
Under this alternative, livestock grazing would not occur so there would be no direct livestockinduced
effects to the vegetation and soils of the project area, including those of riparian areas and
wetlands. The existing plant communities would proceed along their current successional pathways,
which would bring about changes in their composition, structure, and function. As is the case for all
alternatives, natural disturbances including fire, disease, insects, and weather events are likely to
occur and change ecological conditions in the vegetation types of the project area.
The vegetation types of the project area would benefit from reduced livestock grazing intensity
(Holechek 1981, McNaughton 1983) since grazing and overgrazing by sheep, and sheep impacts
from trailing and bedgrounds would not occur. Grazing intensity is defined by Holechek et al. 1998
as the cumulative effects grazing animals have on rangelands during a particular time period. This
would allow native forage plants (particularly forbs) to increase their vigor and root reserves, which
would increase their chances for survival by increasing their ability to reproduce, compete, and
withstand drought, disease, fire, and grazing (Heitschmidt and Stuth 1993). An increase in the
abundance and vigor of plant species would increase the amount of ground cover (vegetation and
litter), which would likely increase infiltration, and decrease runoff and erosion.
This alternative would result in improved ecological conditions compared to current conditions,
since the sites where adverse effects from sheep trailing and sheep bedding are occurring would
likely improve. Also under this alternative, the desired conditions for BLM lands and Forest Service
lands would continue to be met.
Noxious weeds would continue to be present in the analysis area under this alternative. Permitted
livestock would no longer contribute to the spread of noxious weeds, but recreational stock, wildlife
and a wide variety of other sources would continue to spread noxious weeds. The spread of
populations would be more dependent upon treatment intensity than upon livestock grazing.
60

Treatment of noxious weeds would continue whether livestock grazing occurs or not. Livestock
would no longer be indirectly contributing to the spread of weed populations by creating conditions
that foster establishment of weeds, such as patches of bare soil, and reductions in vegetative cover
and competition.
There would be no impacts from permitted livestock grazing to threatened, endangered, proposed,
candidate, or sensitive plant species because there would be no permitted livestock grazing under
this alternative.
Alternative 2
Under this alternative, livestock grazing intensity (defined in Alternative 1) would be low in most
places. Sheep would graze (consume the leaves and shoots of plants) and sometimes overgraze (the
continued utilization of an excessive amount of the current years plant growth which exceeds the
recovery capacity of the plant) forage plants in the project area (particularly forbs), which would
decrease the photosynthetic abilities of the grazed plants by decreasing the leaf areas necessary for
performing this function (Heitschmidt and Stuth 1993, Caldwell et al. 1981, Briske and Richards
1995). Defoliation would cause a reduction of carbohydrate pools within the root systems of the
grazed plants, which would reduce root growth and nutrient absorption. A reduction in
photosynthesis and carbohydrate pools would decrease plant vigor and productivity and decrease the
grazed plants chances for survival by decreasing their ability to reproduce, compete, and withstand
drought, disease, fire, and grazing (Briske and Richards 1995).
A significant decrease in the abundance and vigor of plant species due to sheep grazing and
trampling (which often occurs at bedgrounds) would decrease the amount of ground cover
(vegetation and litter) and increase the amount of bare soil, which could reduce infiltration (Lull
1959, Smith 1967, Dadkhah and Gifford 1981), and increase runoff and erosion (Lull 1959, Orr
1975, Dunford 1954, Smith 1967, Forsling 1931).
This alternative would result in ecological conditions that are similar to current conditions since the
livestock grazing intensity, timing, and the rotation grazing system would remain the same. Since
sheep spend most of their time in the turf type, the potential for adverse effects from sheep grazing
would be greater there compared to the other alpine vegetation types. But adverse effects to plants
and soils from sheep grazing and trampling in all the vegetation types in the project area (including
the turf type, riparian areas, and wetlands) would be minor. Adverse effects to plants and soils from
sheep trailing and sheep bedgrounds would likely continue, but they would be minor. Also under this
alternative, the desired conditions for BLM lands and Forest Service lands would continue to be met.
Noxious weeds would continue to be present in the analysis area under this alternative. Permitted
livestock would continue to be one of the factors in the spread of noxious weeds, along with the
other sources of weed spread. As with Alternative 1, the spread of noxious weed populations would
be more dependent upon treatment intensity than upon livestock grazing.
There would be no impacts to threatened, endangered, proposed, or candidate plant species from
livestock grazing associated with these alternatives because there are none of them in the project
area and no habitat for them in the project area.
Potential effects of these alternatives to Sensitive Species Eriophorum altaicum var. neogaeum,
Parnassia kotzebuei, Machaeranthera coloradoensis, Cryptogramma stelleri, Carex viridula,
Eriophorum chamissonis, Eriophorum gracile, and Gilia sedifolia include injury or death to
individuals resulting from trampling or foraging by sheep, and disturbance to the habitat of these
species due to trampling by sheep which may also create conditions that are conducive to the
establishment of invasive plant species that can compete with native species for habitat resources,
which could lead to a decrease in the number of individuals of these species if they are present. It is
61

unlikely that any of these species will be adversely affected by sheep because Machaeranthera
coloradoensis and Gilia sedifolia occur in remote places sites where sheep are unlikely to go, and
because sheep tend to not spend much time in wetlands where Cryptogramma stelleri, Carex
viridula, Eriophorum chamissonis, Eriophorum gracile, Eriophorum altaicum var. neogaeum and
Parnassia kotzebuei occur.
Alternative 3
Under this alternative, livestock grazing intensity (defined in Alternative 1) would be low. Sheep
would graze and sometimes overgraze forage plants in the project area (particularly forbs), as
described in Alternative 2, but the reduced livestock grazing intensity (compared to Alternative 2)
would reduce the potential for overgrazing and trampling which often occurs at bedgrounds, and
allow forage plants to increase their vigor and root reserves, which would increase their chances for
survival by increasing their ability to reproduce, compete, and withstand drought, disease, fire, and
grazing (Heitschmidt and Stuth 1993). Increasing the abundance and vigor of plant species would
increase the amount of ground cover (vegetation and litter) and decrease the amount of bare soil,
which would likely increase infiltration, and decrease runoff and erosion.
This alternative would result in improved ecological conditions compared to current conditions
(Alternative 2) since the livestock grazing intensity, timing, and the rotation grazing system would
change, resulting in a decrease in the frequency and duration of sheep use. Since sheep spend most
of their time in the turf type, the potential for adverse effects from sheep grazing would be greater
there compared to the other alpine vegetation types. But adverse effects to plants and soils from
sheep grazing and trampling in all the vegetation types in the project area (including the turf type,
riparian areas, and wetlands) would be minor. Adverse effects to plants and soils from sheep trailing
and sheep bedgrounds would not occur or would be minor. Also under this alternative, the desired
conditions for BLM lands and Forest Service lands would continue to be met.
The impacts to vegetation and soils from closing allotments would result in ecological conditions
that are similar to current conditions since livestock have already been absent from these allotments
for many years.
The impacts of reducing the season of use, reducing sheep numbers, reducing the number of days of
sheep utilization, resting from sheep grazing, and seeding herbs into the project area (all of which
could be implemented in the future under adaptive management) would result in improved
ecological conditions for the vegetation and soils of the project area, since all these management
actions would reduce grazing intensity and the associated adverse effects to plants and soils, increase
the abundance and distribution of desirable native herbs, and decrease bare soil.
Noxious weeds would continue to be present in the analysis area under this alternative. Permitted
livestock would continue to be a factor in the spread of noxious weed seeds, along with the other
uses in the analysis area. As with Alternatives 1 and 2, the spread of noxious weed populations
would be more dependent upon treatment intensity than upon livestock grazing. This alternative
provides the adaptive option for introduction of biological control to the worst locations of
infestation. While biological control would help to decrease the vigor and spread of noxious weeds,
it would not eliminate them.
Impacts from livestock grazing to threatened, endangered, and sensitive plant species would be the
same as under Alternative 2.
CUMULATIVE IMPACTS
Current conditions of the vegetation and soils of the project area have resulted from many
management activities (other than livestock grazing) over time including timber harvest, recreational
62

wildlife grazing, recreation, fire suppression, fuels treatments, and fire. Natural disturbances
including insect and disease outbreaks, wind events, fire, landslides, and floods have also had an
influence. All these activities have contributed to changes in the composition, structure, and function
of the vegetation of the project area and have disturbed soils to some extent. These activities will
continue into the foreseeable future resulting in additional changes to the composition, structure, and
function of the vegetation and the soils of the project area.
Many other activities have contributed to noxious weed increases on the landscape. Activities such
as road building, off road vehicle use, dispersed and developed recreation, mining activities, and
drought contribute to weed establishment and spread. If current levels of weed suppression activities
continue, populations of weeds in general will remain stable or increase.
Recreation ______________________________________
AFFECTED ENVIRONMENT
The project area is divided into 14 grazing allotments. Within these allotments current recreation
activities include: driving for pleasure via 4x4s, OHVs, and regular passenger vehicles; hiking;
backpacking; horseback riding; fishing; camping (dispersed and in developed FS campgrounds);
viewing wildflowers and historical sites; white-water boating; skiing (downhill and backcountry);
snowmobiling and snowshoeing. The San Juan Scenic Byway (U.S. Hwy. 550) and the Alpine Loop
(Silverton, Ouray, and Lake City 4x4 roads) provide scenic motorized routes and access points to the
above activities. Approximately 68,500 acres of the Weminuche Wilderness, the largest in the State
of Colorado, are within the analysis area.
Four of the allotments are proposed to be closed (Little Molas/West Needles, Minnie Gulch, Needle
Mountains, and West Lime) and two are to be converted to forage reserve status (Flume and
Graysill). This analysis will only address those impacts to recreation and wilderness resources in the
proposed active allotments (Red Mountain, Gladstone, Eureka, Picayne/Mineral Pt., Maggie Gulch,
Deer Park, Elk Creek and Engine Creek/Deer Creek) and in the forage reserve allotments.
The following discussion of affected environment is grouped by general geographic area and type of
recreational use.
Red Mountain, Gladstone, Eureka, Picayne/Mineral Pt. and Maggie Gulch Allotments
These five allotments are very similar in that they consist of steep slopes, alpine and sub-alpine ecosystems,
4x4 roads and historical mining remnants. The recreation use within these allotments
includes driving for pleasure via 4x4 roads and highway, viewing scenery, wildlife and historical
mining sites; dispersed camping, hiking, and winter sports. The historic mining town of Animas
Forks with standing structures (in the Eureka Allotment), offers an easily accessible historic site.
There is “self guided” tour information available and toilet facilities at this location. It is the most
heavily visited historic site within this analysis area, accessible by vehicle. The travel management
designation for the FS lands is “B”, which prohibits off road travel by motorized vehicles except for
snowmobiles over snow. The BLM lands are in a “limited” travel management designation
requiring all motorized use to stay on designated roads.
The town of Silverton is a destination summer vacation spot and during summer and fall (June -
October) the use on the public lands surrounding Silverton is high. Winter use (December - April)
has increased with the development of the Silverton Mountain Ski Area. Due to the increased
numbers of backcountry skiers and snowmobilers, winter use has increased from moderate to high in
the Red Mountain and Gladstone areas, especially on weekends.
63

Recreation Special Use Permits for outfitters and guides include horseback rides, jeep tours, ATV
tours, backpacking, backcountry skiing, avalanche courses, heli-skiing, and downhill extreme skiing.
Special events include foot races, jeep events, and portions of the Hard Rock 100, a long distance
endurance foot race. There are approximately 12-14 outfitter-guide and special event permits issued
for this area.
Deer Park and Elk Creek Allotments
Large portions or approximately 12,300 acres of the Deer Park and Elk Creek Allotments are inside
the Weminuche Wilderness, designated by Congress in 1975 (Figure 1-7). These two allotments are
high elevation alpine ecosystems with short growing seasons and heavy snowfall which often stays
late in the spring and early summer.
The National Forest system trails: Continental Divide Trail (#813), Highland Mary Trail (#502), Elk
Creek/Colorado Trail (#503) and the Whitehead Trail (#674) provide access for foot and horse users.
The Elk Creek and Highland Mary Trails receive heavy use; the Continental Divide Trail receives
moderate use and Whitehead Trail receives low use during the summer season. User-created trails
exist within this area and for the most part were made by sheep and sheep permittees. They are
occasionally found and used by the public. The Wilderness Act of 1964 establishes the travel
management designation for these portions of the allotments, prohibiting motorized or mechanized
travel within designated wilderness.
Recreation Special Use Permits for outfitter-guides include educational backpacking, llama hiking,
and horseback riding activities. There are no recreation event permits issued in wilderness.
The remaining 7,700 acres of the Deer Park and Elk Creek Allotments are BLM lands and include
the Kendall Mountain, Deer Park and Stony Pass 4x4 roads, and the Cunningham Gulch road. These
roads are regularly traveled during summer and fall but are not as heavily used as other 4x4 roads in
the area. Along the Cunningham Gulch road there are some flat valley sections where dispersed
camping occurs (near and adjacent to the corrals) and at the end of this road is a trailhead for the
Highland Mary and Continental Divide trails. There is approximately two miles of the Continental
Divide trail (north from Stony Pass) within this allotment.
The travel management for these BLM lands is “limited” which requires motorized vehicles to stay
on designated roads. During the winter months (December-April), snowmobiling, backcountry
skiing, snow boarding and snowshoeing are the main recreational activities with a moderate amount
of use. The steep terrain combined with high avalanche danger limits winter use. During summer
and fall (June - October) the recreational use within this allotment is high.
Recreation Special Use Permits for outfitters and guides include educational backpacking groups,
guided hunting, jeep tours, ATV tours and horseback rides. Special events include parts of the
Hardrock 100 endurance foot race and jeep events.
There are two Wilderness Study Areas (about 3,000 acres) on BLM lands adjacent to the
Weminuche Wilderness in the Deer Park Allotment, which are to be managed to maintain their
wilderness characteristics. They are currently monitored annually to document current use and
activities and ensure their wilderness characteristics.
Engine Creek/Deer Creek, Flume and Graysill Allotments
Spring, summer, and fall (May-November) recreation use within the Engine Creek/Deer Creek
Allotment includes hiking, bicycling, backpacking, horseback riding, dispersed camping, and
hunting. There are no Forest roads within this allotment and it is managed for semi-primitive nonmotorized
recreation activities. Vehicle access is from the Little Molas Lake Road (#979 ) and the
Cascade Creek Road (#783). Trails in this allotment provide approximately 30 miles of non-
64

motorized opportunities and include: Colorado Trail (#507), Deer Creek Trail (#678), Coal Creek
Trail (#677), Pass Creek Trail (#500), Engineer Mtn Trail (#508), and Cascade Creek Trail (#510).
The use on the Pass Creek, Cascade and Colorado Trails is high with the remaining trails seeing
moderate amounts of use. Backcountry skiing, snowshoeing and hybrid snowmobile/skiing occur
during winter months in portions of this allotment. The travel management designations are “A”,
where no motorized travel can occur at any time of the year, and “B” where snowmobiles during the
winter can travel.
Recreation Special Use Permits for outfitters and guides include educational backpacking groups,
guided hunting, horseback rides, and bicycle tours. Special events include endurance foot, bicycle
and uphill ski races.
Within the Flume and Graysill Allotments, recreational uses include driving for pleasure, hiking,
backpacking, horseback riding, bicycling, dispersed camping, hunting and historic site viewing.
Cascade Divide Road (#579) and the upper two miles of Hermosa Park Road (#508) offer two scenic
roads for motorized travel. Forest Road 508 goes over Bolam Pass to U.S. Hwy. 145, passing by the
Graysill Mine and provides access to the Colorado Trail (#507). Use is heavy in the summer season
(June - October). In the winter season (November - April) this area is used by snowmobilers and
backcountry skiers and use is moderate.
Recreation Special Use Permits for outfitters and guides include educational backpacking groups,
guided hunting, jeep and bicycle tours, and snow cat skiing in the winter. Special events include
endurance foot, bicycle and cross-country ski races.
Roadless Areas
The project area includes approximately 72,000 acres of inventoried roadless areas. These areas
were inventoried for suitability of roadless characteristics in 2000, as part of the President’s
Roadless Initiative (36 CFR 294). The inventory was updated in 2009 as part of the Colorado
Roadless Rulemaking process, resulting in 54,000 acres of inventoried roadless areas (Figure 1-7).
The reduction in acres is due primarily to removal of wilderness acres in the tally. These areas may
contain some primitive old roads that are not maintained as part of the Forest Service classified
system of roads.
ENVIRONMENTAL CONSEQUENCES
Alternative 1 –No Action
Recreation impacts from the removal of sheep grazing in this landscape would eliminate the conflict
that exists between recreationists and livestock grazing operations. There would be no sheep on
system trails, no conflicts with guard dogs, no continued trailing and bedding and no sheep at
popular lakes. The vegetation loss and soil compaction from trailing and bedding would restore itself
over time, or at least be given the opportunity to heal. The wildflowers would remain for viewing
throughout the growing season. Those people who feel that a “primitive” or “pristine” experience in
the backcountry or wilderness should not include sheep would have an improved experience. The
removal of livestock grazing would not affect the suitability of inventoried roadless areas or
Wilderness Study Areas. Some visitors who enjoy and appreciate the “old west” experience and
cultural history of livestock grazing would miss the presence of sheep and sheepherders.
Alternative 2
Under this action alternative, the level of impacts on recreation in the project area would continue as
they currently exist and would increase as the numbers of recreationists increase. For some visitors,
the presence of sheep, the visible signs of grazing (trailing, tramping of vegetation and wildflowers),
along with the noise, and negative sheep dog encounters are undesirable. Continuation of current
65

livestock management would not change impacts to recreationists. Currently sheep herders keep the
sheep away from the historic mining town of Animas Forks and do not bed sheep near lake shores
helping to mitigate sheep and recreation users from mixing at busy recreation sites.
Wilderness impacts to vegetation from trailing and bedding (loss of vegetation and soil compaction)
would continue to occur in “pristine” management areas of the Weminuche Wilderness. The system
trails, especially the Continental Divide Trail, would continue being used and crossed by sheep. As a
result, damage to the trail tread and trail widening would continue. Non-system trails would
continue to be used within 1.1-pristine management areas where Wilderness Direction states that
none shall exist. The solitude experience sought by many wilderness users may be impacted if
during their trip, they encounter or camp within sound of a band of sheep. The ingress and egress of
the sheep would occur in the same locations, which can cause recreation user impacts at the
Cunningham corrals. Conflicts that occur with recreational users within this analysis area would
continue to occur.
Roadless Areas
There would be no impacts to roadless areas under either action alternative, nor would livestock
grazing affect the suitability of inventoried roadless areas or Wilderness Study Areas. There are no
actions proposed for any livestock grazing purposes that would be prohibited by roadless area
protection.
Alternative 3
The impacts to recreation from Alternative 3 would help to alleviate some of the recreation/livestock
issues. Allotment-specific design criteria would reduce recreational impacts compared to Alternative
2:
Deer Park Allotment
• By reducing the time spent on the west side of the Highland Mary Lakes basin, not allowing
bedding within ¼ mile of the lakes in this allotment, and changing the allotment boundary to
move the sheep into different areas, the impacts to the vegetation and the recreationists
should be reduced.
• Additional changes that might occur after 2-3 grazing seasons would change the
ingress/egress route to Kendall Gulch, and/or change the class of livestock to yearlings; this
would reduce the amount of time a user would encounter sheep and leave less sign
(trampling of vegetation and wildflower loss) after the sheep pass through the wilderness,
helping to improve the experience desired by some users.
• Additional changes that might occur after another 2-3 grazing would remove the Highland
Mary lakes basin from grazing and reduce the total grazing season; these changes would
greatly reduce the recreation/livestock impacts discussed in Alternative 2. This high-use lake
basin would have no livestock and no direct recreation/livestock encounters or impacts.
• Through applying different grazing rotations in Spencer Basin and Highland Mary Lakes
during high use times, improvements to the recreationist from grazing impacts would
improve.
Elk Creek Allotment
• By minimizing the use of the Continental Divide trail by sheep, the impacts to the trail would
improve, or not worsen, and future tread and drainage work on the trail would be more
effective to maintaining the trail to standard.
Engine Creek/Deer Creek
66

• Avoiding Little Molas Campground and minimizing use of the Colorado Trail would be
beneficial to recreational.
Eureka
• Avoiding Animas Forks on weekends and holidays and trailing around the townsite would
reduce conflicts with recreational use and vehicular traffic.
There are also several general design criteria that are found in Alternative 3 that would help to
reduce conflicts with recreation and improve wilderness experience:
• Bedding away from streams, lakes, system trails, campgrounds or picnic grounds would help
to alleviate conflicts. These types of areas are higher-use recreational areas, therefore
avoiding sheep bedding at those locations would reduce impacts like vegetative trampling,
noise, and dog encounters.
• Working dogs would be under the herders control and non-threatening to people, when
people are not within the bounds of the grazing sheep band, and the number of dogs would be
limited. Dogs not meeting this requirement would be removed.
• Signing at trailheads to inform users where they would encounter sheep during certain
timeframes would allow hikers to avoid sheep if they choose to.
• Educational information would be available to the recreating public to help them understand
how to avoid unpleasant encounters with sheep and working dogs.
The allotments that are proposed for closure will provide approximately 92,500 additional acres
where visitors could avoid livestock grazing and its impacts altogether. Included in the areas
proposed for closure are high-use recreation areas including the South Mineral drainage and
campground, Ice Lakes Basin, Little Molas campground, Andrews Lake, the Animas River Corridor,
and Chicago Basin.
In general, because of increased flexibility in adaptive livestock grazing management and expected
better implementation, Alternative 3 would result in better resources conditions and fewer impacts to
recreationists and wilderness than Alternative 2.
Roadless Areas
There would be no impacts to roadless areas under either action alternative, nor would livestock
grazing affect the suitability of inventoried roadless areas or Wilderness Study Areas. There are no
actions proposed for any livestock grazing purposes that would be prohibited by roadless area
protection.
CUMULATIVE IMPACTS
Activities that have affected recreation within the Silverton landscape include past and on-going
sheep grazing, and past mining, and on-going recreational use. These activities cause loss of
vegetation, visual impacts, noise, and waste while in operation, and lasting visual impacts for years
afterwards. Past mining can also be considered to have created a recreational destination for those
who enjoy visiting the historic structures and using the roads originally creating for that purpose.
Silverton Mountain Ski Area has been operating since 1999, and has created new recreational
opportunities for extreme nordic skiing. There are also heli-skiing operations occurring in the
Silverton landscape.
67

Concurrent to this grazing analysis, the BLM is updated the Alpine Triangle Recreation Area
Management Plan, which sets management direction for the Silverton area. The updated plan will
likely make minor adjustments to management emphasis in certain areas, and will update guidance
to include current uses.
Travel management in the Silverton landscape area will undergo the public planning process in the
near future in order to meet the new Forest Service travel management rule. This rule requires that
all motorized travel occur on designated trails and roads. The planning process will utilize the
Forest Plan direction which will display areas suitable for motorized travel. Because the Silverton
landscape already has limited off-road motor vehicle use, this would likely have only minor impacts
on recreation use in the Silverton area.
Under the on-going Land Management Plan revision process, proposal may be made that would
change suitability determinations for the types of recreation or other activities in the landscape.
Wildlife – Threatened and Endangered Species _______
AFFECTED ENVIRONMENT
A Biological Assessment (BA) was conducted to evaluate the potential effects from domestic
livestock grazing in the Silverton Landscape to federally listed threatened or endangered fish and
wildlife species, species proposed for federal listing, and designated critical habitat, as designated by
the U.S. Fish and Wildlife Service (Schultz 2009a). The BA addresses those listed species and/or
their critical habitat that are known to occur or have the potential to occur on the San Juan National
Forest and/or BLM Field Office, or are known to occur downstream and have the potential to be
affected by actions proposed to occur on San Juan Public Lands.
Analyzing and disclosing the effects of the proposed action to federally listed species is needed to
comply with the Endangered Species Act of 1973 (16 U.S.C.1531 et seq.), as amended; BLM
manual 6840 direction for special status species management; the National Forest Management Act
of 1976 (including FS Manual 2670 direction for threatened, endangered, and sensitive species
management); and the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C.4321 et seq.),
as amended.
A BA is the means to review, analyze, and document the direct, indirect and cumulative effects to
federally listed species, species proposed for federal listing, or designated critical habitat for listed
species. The full BA for this project can be found in the project record (Schultz 2009a). The section
below summarizes the findings of the BA.
Federally listed species addressed in the BA are from the most recent list received from the USFWS
(USDI 2009). There are no species proposed for listing under the Endangered Species Act, nor is
there any designated critical habitat for any listed species in the Silverton Landscape.
There are eight species listed as threatened or endangered that have the potential to occur or be
affected by projects on the Columbine Ranger District and BLM Field Office (Table C-1, Appendix
C). Five of these species do not have habitat in the Silverton Landscape and are not affected by the
proposed actions: Mexican spotted owl, razorback sucker, bonytail chub, Colorado pikeminnow, and
Humpback chub. For this reason, these five species were dropped from further evaluation and the
effects determination for these five species was “no effect.”
68

ENVIRONMENTAL CONSEQUENCES
The Canada lynx, southwestern willow flycatcher, and Uncompahgre fritillary butterfly are the only
federally listed species with suitable habitat in the Silverton Landscape. Therefore they were carried
forward for additional analysis. Information on the habitat requirements, status, distribution,
abundance, threats, and key habitat components of these species is included in the BA and will not
be reviewed here.
For Canada lynx, there is a total of about 75,100 acres of suitable lynx habitat in the landscape, of
which about 18% (15,900 acres) is suitable for livestock grazing under current management. The
landscape intersects five Lynx Analysis Units (LAUs), the Animas River Headwaters LAU, Cascade
Creek LAU, Hermosa Creek LAU, Needles LAU, and Silverton LAU. The landscape also intersects
four mapped lynx linkage areas, Silverton-Lake City, Red Mountain/South Mineral, Molas-Coal
Bank, and North La Plata Mountains.
For southwestern willow flycatcher, there is a total of about 150 acres of potential flycatcher habitat
on Federal lands in the landscape. Of this, a total of about 116 acres is in closed allotments or vacant
allotments that are proposed for closing under the proposed action. About 34 acres of potential
flycatcher habitat is in three active livestock grazing allotments. Of the 33 acres in active livestock
allotments, only 1.3 acres are in areas suitable for domestic sheep grazing. The remaining 32.7 acres
are in areas unsuitable for sheep grazing.
For Uncompahgre fritillary butterfly, there are no known butterfly colonies in the Silverton
Landscape, although snow willow is widely distributed and relatively abundant in the alpine zone
across the landscape. The landscape has been extensively surveyed for butterflies over many years
and no colonies have been located. There is however, one location in the landscape that appears to
have suitable habitat attributes and the potential for butterfly occurrence seems high. This site has
been visited but conclusive survey results were not obtained. For this reason, until the site can be
conclusively surveyed the site will be presumed to be occupied by butterflies and domestic sheep
will be managed accordingly.
Alternative 1 –No Action
Alternative 1, the No Action Alternative, would be wholly beneficial for all three federally listed
species because domestic sheep grazing would not be re-authorized in the Silverton Landscape.
There would be no potential impacts from sheep grazing activities to key habitat components for
listed species. Selection of Alternative 1 has the potential to provide direct benefits to listed species
but the degree of benefit would probably be small in any given year and limited in scale on the
landscape. Benefits to listed species from selecting Alternative 1 would probably be long term (> 10
years). Benefits to listed species from selecting Alternative 1 would probably be most pronounced
for Canada lynx at or near the spruce-fir forest/alpine interface. Benefits to Uncompahgre fritillary
butterfly would probably be less pronounced than for Canada lynx because the one area where
butterflies might occur in the landscape shows little sign of impacts from current sheep grazing
practices. Field visits to the three active allotments containing potential flycatcher habitat failed to
find any habitat patches that meet the US Fish and Wildlife Service minimum flycatcher patch size
of 30 feet by 30 feet by average 5 feet in height in areas that are regularly grazed by domestic sheep.
Because environmental reasons not related to sheep grazing indicate that potential for flycatcher
occupancy is low, improvements in flycatcher habitat capability from selecting Alternative 1 are
likely to be gradual, long term and limited to a few localized areas.
69

Alternative 2
Habitat conditions for listed species would be expected to continue to gradually improve under
Alternative 2 because there has been a continued decline in the number of domestic sheep grazed in
the Silverton Landscape over the past 40 years. Numbers of domestic sheep grazing in the Silverton
Landscape have dropped about 51% from a high of about 16,000 animals in the 1960’s to about
8,230 currently. In addition, numbers of sheep grazing on the San Juan National Forest have
dropped about 95% from a high of about 216,600 animals in the 1930’s to about 10,800 currently.
Selecting Alternative 2 would have both positive and negative effects for listed species. Selecting
Alternative 2 would have beneficial effects for listed species because current livestock management
practices would maintain current gradual improvement in habitat capability for listed species across
much of the landscape, especially when compared to historical livestock management practices.
Alternative 2 would also have negative effects for listed species, compared to Alternative 1, because
a few localized areas would continue to be affected by sheep grazing activities, such as in some
spruce-fir stands near the alpine interface. Selecting Alternative 2 would be generally beneficial for
listed species, but less so than selecting Alternative 1 because improvement in habitat conditions
would probably occur over a longer time frame than under Alternative 1. In general, habitat
conditions are expected to gradually improve in most areas under Alternative 2 but impacts to
habitat for listed species would continue in a few localized areas.
Alternative 3
Selecting Alternative 3 would be generally beneficial for listed species, although likely considerably
less than under Alternative 1 but probably somewhat more beneficial than selecting Alternative 2.
The improvements in habitat conditions for listed species expected to occur over time under
Alternative 3 are likely to be generally small and limited to a few localized areas where habitat
conditions are being affected by sheep grazing activities under current management practices. For
example, under Alternative 3 there would be a 31% reduction in the acres of alpine and spruce-fir
habitats suitable for domestic sheep grazing (about 27,700 acres), compared to Alternative 2 (about
40,100 acres). Under Alternative 3 only 18% of the lynx habitat in the Silverton Landscape would
occur in areas suitable for livestock grazing.
Similar to Alternative 2, selecting Alternative 3 would have both positive and negative effects for
listed species. Selecting Alternative 3 would have beneficial effects for listed species because
application of adaptive management strategies and project design criteria should result in more rapid
improvements in habitat conditions in some localized areas where sheep grazing impacts are
currently occurring. Also similar to Alternative 2, Alternative 3 would have negative effects for
listed species, compared to Alternative 1, because a few localized areas would continue to be
affected by sheep grazing activities, such as in some spruce-fir stands near the alpine interface.
Selecting Alternative 3 would be generally beneficial for listed species, more so than selecting
Alternative 2 but less than selecting Alternative 1 because improvement in habitat conditions would
probably occur over a longer time frame than under Alternative 1. In general, habitat conditions are
expected to gradually improve in most areas under Alternative 3 but impacts to habitat for listed
species would continue in a few localized areas.
During the 2008 field season, a total of 28 vegetation monitoring points were sampled across the
eight livestock allotments in the Silverton Landscape that would be open to sheep grazing under
Alternative 3. Eight of the nine RHM samples met the desired conditions, with one (FS Deer Park
Allotment) at risk, but moving towards meeting the desired condition. Eleven of 12 of the LHA
samples met desired conditions, with one (Picayne/Mineral Point Allotment) not meeting desired
conditions. All seven of the riparian proper functioning condition samples in riparian areas on FS
70

and BLM lands met the desired conditions. Therefore in total, of the 28 vegetation condition
samples conducted during the 2008 field season, 26 met the project’s desired conditions and two did
not meet the project’s desired conditions.
Compared to Alternative 2, the application of adaptive management strategies and project design
criteria under Alternative 3 should result in more rapid improvements in habitat conditions in some
localized areas where sheep grazing impacts are currently occurring because adaptive management
strategies would not be fully applied under Alternative 2. Although more rapid improvement in
habitat conditions for listed species is expected under Alternative 3 than under Alternative 2,
improvements in habitat conditions as a result of the adaptive management approach are likely to be
too small to affect populations or the total amount of habitat available in the Silverton Landscape.
Domestic sheep grazing does not appear to be having measurable direct or indirect effects to Canada
lynx habitat in closed canopy spruce-fir and cool-moist mixed conifer forests in the Silverton
Landscape. In general, sheep spend little time in these areas because of the lack of forage under
closed canopy conifer forests. The few areas of noticeable sheep grazing impacts in closed canopy
spruce-fir forests were found to be small in scale and limited in scope where sheep rested near the
edges of parks or alpine zones. For this reason, domestic sheep grazing under Alternative 3 and
Alternative 2 is not likely to substantially adversely impact habitat structure for lynx primary prey,
such as younger age class conifers used by snowshoe hare in winter, or downed log piles and other
woody debris used as hare cover and lynx denning habitat.
Most of the willow riparian areas (potential habitat for Canada lynx and southwestern willow
flycatcher) across the landscape are currently in upper mid-seral successional stage, or are in an
upward trend and therefore are meeting land management plan direction for riparian condition.
Little evidence of willow browsing was observed in willow dominated riparian areas at or near
timberline. All seven of the riparian monitoring points visited during the 2008 field season met the
project’s desired conditions. Sheep readily browse on willows in riparian and wetland areas and
some heavy browsing was observed on willows in a few localized areas. However it was difficult to
determine with certainty whether the primary cause of this browsing was domestic sheep or elk
because both were present in these localized areas.
Sheep trailing was also evident in some riparian and willow dominated areas but current plant
species composition and distribution are likely similar to conditions found during the reference
period. Overall, the effects of sheep grazing and trailing in riparian and wetland areas appears to be
small and/or limited to localized areas. For these reasons, selection of Alternative 3 would be
generally beneficial to lynx and flycatcher habitat conditions, compared to Alternative 2, but the
benefits would probably be small and localized in scale but continue to improve over the long term
(10+ years).
Under Alternative 3, a “restricted area” polygon has been delineated around the area where
Uncompahgre fritillary butterfly might occur. Under this alternative, domestic sheep activities
would be restricted to allow only trailing under controlled circumstances through this polygon; no
bedding, salting or intentional grazing would be permitted within the polygon to ensure that sheep
grazing does not degrade butterfly key habitat attributes. This “restricted area” polygon was
designed to have boundaries that could be readily identified on the ground by sheep herders
managing the flocks.
Monitoring of domestic sheep grazing patterns in and near the “restricted area” polygon in summer
2008 found no evidence that domestic sheep grazing was affecting snow willow abundance,
distribution or plant vigor. The minor use of the restriction area polygon by sheep from an adjacent
allotment did not appear to be impacting alpine plant abundance or species diversity. Grazing
71

intensity on alpine plants appeared to be well within desired conditions. There was no evidence of
recent bedding, salting or sheep trailing in the “restricted area” polygon. For this reason, design
criteria applied under Alternative 3 should provide for continued gradual improvement in butterfly
habitat conditions over time.
CUMULATIVE IMPACTS
Intensive historic levels of livestock grazing, increasing levels of jeep and OHV traffic on most
roads in the landscape, development of private lands within surrounding Federal lands, water
diversion, and 100 years of surface and subsurface mining operations have likely contributed to
substantial cumulative effects in lynx and flycatcher habitat. Some of the impacts of these past
activities have been reduced or mitigated through natural re-vegetation of formerly impacted areas
and improvements in water quality as abandoned mines have been reclaimed.
Mining was the past human activity that likely had the most extensive and negative impact on lynx
and flycatcher habitat conditions through out the Silverton Landscape. The effects of more than 100
years of mining have likely been extensive and heavy on willow distribution and structure in the
upper Animas River basin. For example, prior to the advent of mining in the late 1800’s, areas such
as the upper main stem of the Animas River between Howardsville and Eureka probably provided
extensive willow stands capable of supporting flycatchers. Willow stands are gradually revegetating
portions of this area, though the process is slow and few areas yet meet the definition of
flycatcher habitat. Many of the small stream headwaters and upper drainage basins were also
heavily impacted by mining, mostly in the form of water degradation due to mine waste runoff
significantly altering downstream vegetation structure and composition and carrying substantial
quantities of toxic metals that can affect wildlife species and habitat capability directly and indirectly
(Larison et al. 2000). Today, water quality and downstream vegetation structure have been
substantially improved by reclamation activities but remain impaired to varying degrees by mine
tailings and acid runoff from draining adits. Many of these point sources of water quality
degradation are on privately owned lands, and many are long abandoned mining claims on lands
now managed by Federal agencies.
Currently, development of private lands within a surrounding matrix of primarily public lands is
occurring at an increasing rate and is contributing to increased cumulative effects on wildlife habitat
capability and connectivity across the broader Silverton landscape. Most developments are single
family homes for use during snow free seasons. Many of these new recreation residences are being
built in the spruce-fir and alpine habitat types. In addition to increased human presence and activity
in areas formerly removed from human settlement, recreation residences also result in small losses
of primary habitat for listed species. The footprint for most of these residences involves the home
itself, a small cleared or heavily used area around the home, and an access road of varying length
across a steep hillside from an adjacent county road that services the home. Although most use of
these homes is during the snow free seasons, some are also used in winter as overnight huts for
backcountry skiers and snowmobilers and personal recreation by the owners. The residential
development that has recently occurred in the alpine zone does not appear to be affecting domestic
sheep grazing practices or patterns on surrounding federal lands but increased human presence in
winter has resulted in declines in winter habitat capability for some wildlife species. The rate of
development of privately owned parcels in the immediate vicinity of the town of Silverton appears to
be stable or increasing over the past five years as the economy of the town continues to gradually
expand. The amount and distribution of motorized recreation in winter is expected to continue to
gradually expand with corresponding gradual reductions in habitat capability for some wildlife
species. Cumulatively, the proposed action may offset some expected impacts from continued
increased winter use by gradually improving summer habitat conditions for listed species.
72

Human disturbance as a result of increased vehicle and OHV use in the Silverton Landscape also has
potential to impact lynx movement and habitat capability. It is possible that late springtime
motorized use of roads and trails through denning and winter foraging habitat may have negative
effects if lynx are forced to move kittens because of associated human disturbance (Ruggiero et al.
2000). Increased human recreation resulting in more human encounters has potential to increase
lynx mortality. Numbers of motorized users on roads and trails in the landscape is expected to
continue to increase for the foreseeable future, likely resulting in improvements and expansion of
facilities for motorized users. The cumulative effect of increased motorized users and infrastructure
development on habitat capability for listed species is unknown.
Wildlife – Sensitive Species ________________________
Forest Service Manual (FSM) 2670 requires reviews of all Forest Service planned, funded, executed
or permitted programs and activities for possible effects to Forest Service designated sensitive fish
and wildlife species. The process used to evaluate the effects agency activities and programs may
have on designated sensitive species is in accordance with the standards established in 50 CFR
402.12, and Forest Service Manual Direction (FSM 2671.2 and FSM 2672.4). U.S. Forest Service
(USFS) Region 2 sensitive species are designated by the Regional Forester of the Rocky Mountain
Region. BLM policy designates sensitive species to ensure these species receive full consideration
in the NEPA process (BLM 6840 Manual Direction, Release 6-121). BLM sensitive species are
designated by the Colorado State Director. A Biological Evaluation (BE) was conducted to analyze
the impacts of alternatives to designated sensitive species following agency direction (Schultz
2009b).
Table C-2 (Appendix C) lists the species designated as Sensitive by the BLM in the state of
Colorado (USDI Bureau of Land Management 2000) and by the USFS Rocky Mountain Regional
Forester (USDA Forest Service 2009) that are known to occur, may occur, or have habitat on BLM
or NFS lands managed by the San Juan Public Lands Center. Table C-2 also provides a summary of
how the proposed action might affect each species and their key habitat components, and
affect/impact determinations for each species. Specific project affects or impacts are discussed in
more detail for those species with habitat present in the Silverton Landscape and that are likely to be
affected (positively or negatively) by the action alternatives. Details of the analysis leading to the
summary can be found in the project record.
Two species, yellow-billed cuckoo and New Mexico meadow jumping mouse, are also candidates
for listing under the federal Endangered Species Act. Information on the habitat requirements,
status, distribution, abundance and key habitat components of BLM and USFS designated Sensitive
Species is on file at the Columbine Public Lands office in Bayfield, Colorado and will not be
reviewed here.
AFFECTED ENVIRONMENT
There are 45 species identified as sensitive on either the USFS Region 2 or BLM Colorado Sensitive
Species lists. Of these, 42 species are not present in the Silverton Landscape due to the absence of
suitable habitat, or, suitable habitat is present in the landscape, but domestic sheep grazing does not
appear to be affecting the species or its key habitat components. Table C-2 provides rationale for
why some sensitive species were brought forward for detailed project analysis and other species
were not. A total of three species have habitat present in the Silverton Landscape and may be
affected by domestic sheep grazing. The three species brought forward for detailed analysis for this
domestic sheep grazing project include: white-tailed ptarmigan, North American wolverine, and
Rocky Mountain bighorn sheep. Bighorn sheep are discussed in greater detail in this document than
73

the other two species due to the concern regarding possible disease transmission between domestic
sheep and bighorn sheep.
Existing habitat for sensitive species was determined by the use of computer modeling using
vegetative information described in Forest-wide MIS Assessments on National Forest System lands.
Habitat modeling was conducted using habitat structural stage matrices described by Towry (1984).
In addition, information on species’ distribution, professional judgment of FS wildlife biologists,
coordination with Colorado Division of Wildlife (CDOW) biologists, coordination with the U.S.
Fish and Wildlife Service, and field reconnaissance of the project area was also used.
Bighorn Distribution
Rocky Mountain bighorn sheep were historically distributed across the mountainous portions of
Colorado and much of the San Juan Public Lands (Beecham et al. 2007). Desert bighorn sheep are
not known or thought likely to occur in the Silverton Landscape. The Rocky Mountain bighorn
sheep is designated a sensitive species in the U.S. Forest Service Rocky Mountain Region. This
designation is based primarily on potential threats to the long-term viability of bighorn sheep
populations in the Rocky Mountain Region, including diseases transmitted from domestic sheep,
lack of connectivity and/or loss of genetic variability (fitness) due to habitat fragmentation, habitat
loss, increased human disturbance on summer and winter grounds, competition for forage with
domestic livestock, and predation on small isolated herds.
Scientific observation and field studies demonstrate that contact between domestic sheep and
bighorn sheep is possible under range conditions. This contact increases risk of subsequent bighorn
sheep mortality and reduced recruitment, primarily due to respiratory diseases (WAFWA 2007). The
complete range of mechanisms and/or causal agents that lead to disease events in bighorn sheep
cannot be conclusively proven at this time and not all bighorn sheep disease events can be attributed
to contact with domestic sheep (Onderka and Wishart 1984, Aune et al. 1998). However, when
contact between wild sheep and domestic sheep and goats has been documented, the severity of the
wild sheep die-off is typically more pronounced (Aune et al. 1998, Martin et al. 1996). For these
reasons, it is prudent to implement management actions designed to reduce or eliminate the potential
for contact between wild sheep and domestic sheep.
The Silverton Landscape intersects the mapped range of two bighorn sheep herds, S71 the Animas
Canyon Herd, and S33 the Pole Mountain/Upper Lake Fork Herd. There is about 41,430 acres of
mapped overlap between these two herds and domestic livestock allotments in the landscape.
However, it is equally apparent that most domestic sheep grazing and trailing activities in the
Silverton Landscape occurs outside of currently mapped bighorn sheep summer range. Concern for
contact between domestic sheep and bighorn sheep outside of mapped summer range is low because
domestic sheep are present in the landscape only for about a two month period during summer, and
bighorn occurrence outside of mapped summer range is irregular and unpredictable.
The 2007 estimated population size of the Pole Mountain/Upper Lake Fork Herd was about 90
animals (George et al. 2008). Although not well documented, evidence from the Colorado Division
of Wildlife (Diamond 2005) suggests that the S33 Pole Mountain/Upper Lake Fork Herd
experienced a significant and widespread die-off in the late 1980’s. No specific disease monitoring
has occurred in S33, nor have these sheep ever been treated with fenbendazole, an inoculant against
respiratory disease. Based on the high level of recruitment observed in S33, it appears that this
bighorn sheep herd is not experiencing any additive mortality from predation. Habitat quality in the
unit is excellent (Beecham et al. 2007).
Monitoring by the Colorado Division of Wildlife, along with recent (2009) sighting reports indicate
this herd is in an expansion phase (Wait pers. comm.). CDOW believes it is likely that individual
74

ighorns from S33 may pioneer into historic range as the population increases. If so, dispersal and
range expansion may result in bighorns filling vacant habitat and occupying areas where they have
not been documented in recent years, potentially placing S33 at an increased risk for contact with
domestic sheep in nearby active allotments.
S33 is recognized by the CDOW as comprising one large meta-population with S21, the Ouray-Cow
Creek Herd, to the north and west. Together, this meta-population is estimated to be over 200
animals in size. The recently adopted Colorado Bighorn Sheep Management Plan (George et al.
2008) designates S33 as a primary (“Tier 1”) population and ranked as a high priority for
conservation at a statewide level. This designation places S33 and S21 in the top priority for
inventory, habitat protection and improvement, disease prevention, and research. There is no direct
overlap between domestic sheep allotments in the Silverton Landscape and mapped summer range
for the S21 Ouray/Cow Creek herd.
Under current management, the S33 bighorn herd overlaps with 3 active or vacant domestic sheep
allotments: Picayne/Mineral Point (active), Eureka (active), and Minnie Gulch (vacant). All sheep
grazing allotments that overlap with S33 summer range are BLM allotments. No FS grazing
allotments in the Silverton Landscape overlap with S33 bighorn summer range. Together, there is
about 4,877 acres of overlap between these allotments and mapped summer range of the S33 herd.
Within this area of overlap, about 821 acres (17%) are suitable for domestic sheep grazing.
The S71 West Needles Herd was established with animals translocated from the Georgetown Herd in
2000, and 2002-2003. The 2007 estimated population size of the Animas Canyon herd was 75
animals (George et al. 2008), and reproduction and survival have been good (Beecham et al. 2007).
Sheep use the entire Animas River canyon from Rockwood up to Needle Creek, with primary
summer range being the West Needle Mountains, and primary winter and lambing range being the
Animas River canyon from Rockwood up to the Cascade Wye. Immediately after release, two
bighorns dispersed into the S21 Ouray-Cow Creek herd. Based on ear tag observations, several
sheep dispersed into the S33 Pole Mountain/Upper Lake Fork herd. Six or seven sheep moved into
the Hermosa Cliffs area where they have remained and have produced lambs every year.
S71 is considered a translocated herd by CDOW and therefore is lower priority for conservation at a
statewide level (George et al. 2008). As a translocated population, CDOW recognizes the existence
of pre-existing domestic sheep grazing to the north, east, and west of S71, and does not advocate
closure of active domestic sheep allotments on public land based solely on the potential for
interaction between domestic and bighorn sheep (Colorado Division of Wildlife 2009).
Under current management, the S71 bighorn herd overlaps with 6 active or vacant domestic sheep
allotments. Of these, 5 are FS allotments: West Lime (vacant), Little Molas/West needles (vacant),
Needles Mountains (vacant), Flume (vacant), and Deer Creek/Engine Creek (active). One active
BLM grazing allotment, Gladstone, overlaps with mapped summer range for S71. Together, there is
about 36,554 acres of overlap between these 6 allotments and mapped summer range of the S71
herd. Within this area of overlap, about 9,464 acres (26%) is suitable for domestic sheep grazing.
A wildlife review was conducted to analyze the potential impacts to native Rocky Mountain bighorn
sheep of grazing domestic sheep under each of the project alternatives. Details of the analysis
leading to the summary described below can be found in the project record (Schultz 2009b). This
analysis found overlap between mapped ranges for wild bighorn sheep and eight domestic sheep
grazing allotments in the Silverton Landscape.
In the active National Forest Engine Creek/Deer Creek Allotment there is a small area of overlap
with the mapped summer range of the S71 West Needles bighorn sheep herd. Much of the mapped
overlap area is heavily forested and those portions that are part of an old open burn area generally
75

lack bighorn sheep escape cover. The area is also bisected by 2 heavily traveled roads. The mapped
overlap area is normally used by domestic sheep for only 1 day as they come on to the allotment, and
1 day when they leave the allotment.
Prior to 2009, there was no evidence that the portions of the mapped bighorn summer range that
overlap with the Engine Creek/Deer Creek Allotment were regularly used by bighorn sheep.
However, in summer 2009 several small groups of bighorn sheep were observed licking salt along
the side of U.S. Highway 550 about 1.0 mile west of the Lime Creek corral, and slightly outside the
mapped summer range overlap area. This section of highway is closely surrounded on both sides by
a broad band of dense mature spruce-fir forest that is consistent with the description in Schommer
and Woolever (2001) of a continuous forest that could serve as a natural barrier to bighorn sheep
movement. The area has few structures that provide typical bighorn sheep escape cover. This area is
also slightly outside the boundary of the allotment, as it would be modified under Alternative 3.
Under Alternative 2, the close proximity (about 1 mile) of domestic sheep and bighorn sheep near
the Lime Creek corrals in summer 2009 results in a rating of “High Risk” for contact. Under
Alternative 3, the application of project design criteria, use of the Lime Creek corrals only once per
season, and modification of the boundary of the allotment result in a rating of “Moderate Risk” of
contact.
In the vacant National Forest Little Molas/West Needles Allotment there is a significant area of
mapped overlap (about 7,556 acres) between suitable domestic sheep grazing and the S71 West
Needles bighorn sheep herd. The area of overlap is mostly with mapped bighorn summer range but
also with a small portion of mapped summer concentration area on the north end of the West Needle
Mountains. The mapped summer concentration area is regularly used by bighorn sheep, as are
portions of the mapped summer range. Much of the areas of mapped overlap also provide suitable
domestic sheep grazing opportunities, although the allotment has been vacant since 1999. Under
Alternative 2, if the allotment were to be restocked, the substantial area of overlap between known
bighorn sheep use areas and suitable domestic sheep grazing areas results in a rating of “High Risk”
for contact. Under Alternative 3, the allotment would be closed to domestic sheep grazing and the
rating would be “Low Risk” for contact because domestic sheep would not be permitted in the
allotment.
In the vacant National Forest Needles Mountains Allotment there is about 11,898 acres of overlap in
the allotment with mapped summer range of the S71 West Needles bighorn sheep herd. Within this
area, only about 615 acres (5%) is suitable domestic sheep grazing range. The area of overlap is
mostly with mapped bighorn summer concentration and winter range in the center of the West
Needle Mountains. The mapped summer concentration area is regularly used by bighorn sheep, as is
the mapped winter range, even during summer. Much of the area of mapped overlap is very steep
and rocky terrain providing few suitable opportunities for domestic sheep grazing. There are no
records of any permitted livestock being grazed on this allotment. Under Alternative 2, if the
allotment were to be restocked, the substantial area of overlap between known bighorn sheep use
areas and suitable domestic sheep grazing areas results in a rating of “High Risk” for contact. Under
Alternative 3, the allotment would be closed to domestic sheep grazing and the rating would be
“Low Risk” for contact because domestic sheep would not be permitted in the allotment.
In the vacant Flume Allotment there is about 653 acres of overlap in the allotment with mapped
summer range for the S71 West Needles bighorn sheep herd. Within this area, only about 29 acres
(4%) is suitable domestic sheep grazing range. This area of mapped overlap however is heavily
forested with few rock outcrops and provides little suitable habitat for bighorn sheep and little
suitable forage for domestic sheep. The habitats in this portion of the allotment are consistent with
the description in Schommer and Woolever (2001) of a continuous forest that could serve as a
76

natural barrier to bighorn sheep movement. There have been no recent sightings of bighorn sheep in
the mapped overlap area. This allotment has been vacant since 1989. Under Alternative 2, if the
Flume Allotment were to be restocked, the lack of suitable habitat for domestic sheep or bighorn
sheep in or near the zone of overlap, and the distance from the Animas River canyon (about 3.5
miles) results in a rating of “Low Risk” for contact. Under Alternative 3, the Flume Allotment
would be managed as a forage reserve allotment and grazed by domestic sheep on an irregular basis.
Project design criteria would be applied to the allotment when it was active, and the habitat
conditions described above would result in a “Low Risk” for contact.
Most of the vacant BLM Minnie Gulch Allotment is mapped as overlap with the S33 Pole
Mountain/Upper Lake Fork bighorn sheep herd. There is about 2,536 acres of overlap in the
allotment but only about 319 acres (13%) is suitable domestic sheep grazing range. Formal surveys
conducted in the allotment have failed to detect bighorn sheep but the CDOW continues to receive
reports of bighorn sheep in the gulch during summer. It is thought likely that bighorn sheep reported
in the gulch may be coming from the nearby Crown Mountain or Pole Creek Mountain
subpopulations. This grazing allotment has been vacant since 1983. Under Alternative 2, if the
allotment were to be restocked, the substantial area of overlap between mapped bighorn sheep
summer range, regular reports of bighorn occurrence in the overlap areas, and close proximity to
known bighorn use areas results in a rating of “High Risk” for contact. Under Alternative 3, the
allotment would be closed to domestic sheep grazing and the rating would be “Low Risk” for contact
because domestic sheep would not be permitted in the allotment.
In the active BLM Gladstone Allotment there is a small area in the southern end of the allotment that
overlaps with mapped summer range for the S71 West Needles bighorn sheep herd. Under current
management, there is about 320 acres of overlap, with only about 11 acres (3%) being suitable
domestic sheep grazing range. This area of mapped overlap is well removed from areas actually
used by domestic sheep. The area of overlap is immediately adjacent to the town of Silverton. The
area bighorns would have to pass through, and much of the overlap area itself, is consistent with the
description in Schommer and Woolever (2001) of a continuous forest that could serve as a natural
barrier to bighorn sheep movement. Under Alternative 2, the permittee does not use the south end of
the allotment where the zone of overlap occurs due to dense forest cover and lack of forage. For this
reason, the rating for this area is “Low Risk” for contact. Under Alternative 3, the allotment would
be closed to domestic sheep grazing in the south end of the allotment resulting in a “Low Risk” for
contact.
Most of the active BLM Picayne/Mineral Point Allotment is mapped as overlap with the S33 Pole
Mountain/Upper Lake Fork bighorn sheep herd. There is about 2,158 acres of mapped overlap in
this allotment. Within this area, about 378 acres (18%) is suitable domestic sheep grazing range.
Extensive surveys for bighorn sheep have been conducted in the area of overlap over the past four
summer seasons and no bighorn sheep have been detected or reported by the domestic sheep
permittee. Immediately across the Animas River canyon however, surveys have regularly detected
small bands of bighorn sheep using Grouse and Burns Gulches. The bighorn use areas are within ¼
mile of a route permitted for domestic sheep trailing into and out of the allotment under Alternative
2. The allotment is heavily used by the public for motorized recreation with an extensive network of
heavily traveled 4x4 roads and no bighorn sheep have been reported in the area of overlap.
Although much of the allotment is steep, there is little rocky terrain or other structures preferred by
bighorn sheep as escape cover.
Under Alternative 2, the close proximity (about 1 mile) of domestic sheep and bighorn sheep in the
Grouse and Burns Gulch areas results in a rating of “High Risk” for contact in the Picayne/Mineral
Point Allotment. Under Alternative 3, the application of project design criteria, use of the adjusted
77

trailing route, and lack of bighorn sheep sightings in the allotment combine for a rating of “Moderate
Risk” for contact.
In the active BLM Eureka Allotment there is only about 183 acres of overlap with mapped summer
range for the S33 Pole Mountain/Upper Lake Fork bighorn sheep herd. Within this area, only about
43 acres (23%) is suitable domestic sheep grazing range. Surveys for bighorn sheep have been
conducted over the past four summer seasons and no bighorn sheep have been detected or reported
by the domestic sheep permittee. The area is also heavily used by the public for motorized
recreation with an extensive network of heavily traveled 4x4 roads and no bighorn sheep have been
reported in the area of overlap. The area of mapped overlap provides little suitable domestic sheep
grazing opportunities and is well removed from the portions of the allotment that are used by
domestic sheep. Portions of Burns Gulch where bighorn sheep have been detected are about 2.0
miles to the northeast of the mapped overlap area. Crown Mountain and Niagara Peak, known
summer areas for bighorn sheep, are about 3.0 miles east of the allotment, and the Eureka corrals
where the domestic sheep are unloaded and loaded each season are about 1.5 miles from west of
Crown Mountain and only about ¼ mile outside bighorn mapped summer range.
Under Alternative 2, the close proximity of the Eureka corrals and sheep driveway to bighorn use
areas (about 1.5 miles), and the proximity of the mapped overlap area to known bighorn use areas
(about 2.0 miles) combine for a rating of “High Risk” for contact in the Eureka Allotment. Under
Alternative 3, the application of project design criteria, lack of bighorn sheep sightings in the overlap
area, and lack of preferred bighorn habitat in the allotment combine for a rating of “Moderate Risk”
for contact.
ENVIRONMENTAL CONSEQUENCES
Alternative 1 –No Action
Alternative 1, the No Action Alternative, would be wholly beneficial for all designated sensitive
species because domestic sheep grazing would not be re-authorized in the Silverton Landscape.
There would be no impact on habitats used by sensitive species or impacts to individual animals
from selecting Alternative 1. There would be no potential impacts from sheep grazing activities to
key habitat components for sensitive species. Selection of Alternative 1 has the potential to provide
direct benefits to sensitive species but the degree of benefit for most sensitive species would
probably be small in any given year and limited in scale on the landscape. Benefits to sensitive
species from selecting Alternative 1 would probably be long term (> 10 years).
Benefits to designated sensitive species from selecting Alternative 1 would be most pronounced for
Rocky Mountain bighorn sheep in the S33 Pole Mountain/Upper Lake Fork, and S71 West Needles
herds by removing areas of currently mapped overlap with active domestic sheep grazing allotments,
thereby eliminating the possibility of disease transmission between the two species. Selecting
Alternative 1 would also benefit bighorn sheep by removing the possibility of forage competition
between bighorns and domestic sheep. The benefits of selecting Alternative 1 would be long term (>
10 years) and cover extensive areas of currently mapped bighorn sheep summer ranges (about
41,430 acres). Benefits would also come from gradual, long term improvements in the condition of
moist alpine areas adjacent to riparian zones or wet meadows. These potential improvements
however would be limited to a few localized areas where current domestic sheep utilization levels
are high and impacts to soil and vegetation have historically occurred or are continuing to occur.
Benefits to white-tailed ptarmigan would be primarily in improved condition of fall/early winter
foraging and hiding cover in alpine basins, but these improvements would likely be limited in scope
because upland willow stands where browsing impacts were observed were localized and not
widespread. In addition, it was difficult to determine with certainty whether the browsing observed
78

on these willows was done by domestic sheep or elk.
Benefits to wolverine from selecting Alternative 1 would primarily be in improved conditions for
prey species in alpine cirque basins, and reduced disturbance in core wolverine habitat. However,
the benefits to wolverine would be less pronounced than for bighorn sheep or ptarmigan, and would
be limited to a few localized areas. In comparison to the very large average wolverine home range
size, the benefits of selecting Alternative 1 would probably be small.
Alternative 2
Alternative 1, the No Action Alternative, would be wholly beneficial for all designated sensitive
species because domestic sheep grazing would not be re-authorized in the Silverton Landscape.
There would be no impact on habitats used by sensitive species or impacts to individual animals
from selecting Alternative 1. There would be no potential impacts from sheep grazing activities to
key habitat components for sensitive species. Selection of Alternative 1 has the potential to provide
direct benefits to sensitive species but the degree of benefit for most sensitive species would
probably be small in any given year and limited in scale on the landscape. Benefits to sensitive
species from selecting Alternative 1 would probably be long term (> 10 years).
Benefits to designated sensitive species from selecting Alternative 1 would be most pronounced for
Rocky Mountain bighorn sheep in the S33 Pole Mountain/Upper Lake Fork, and S71 West Needles
herds by removing areas of currently mapped overlap with active domestic sheep grazing allotments,
thereby eliminating the possibility of disease transmission between the two species. Selecting
Alternative 1 would also benefit bighorn sheep by removing the possibility of forage competition
between bighorns and domestic sheep. The benefits of selecting Alternative 1 would be long term (>
10 years) and cover extensive areas of currently mapped bighorn sheep summer ranges (about
41,430 acres). Benefits would also come from gradual, long term improvements in the condition of
moist alpine areas adjacent to riparian zones or wet meadows. These potential improvements
however would be limited to a few localized areas where current domestic sheep utilization levels
are high and impacts to soil and vegetation have historically occurred or are continuing to occur.
Benefits to white-tailed ptarmigan would be primarily in improved condition of fall/early winter
foraging and hiding cover in alpine basins, but these improvements would likely be limited in scope
because upland willow stands where browsing impacts were observed were localized and not
widespread. In addition, it was difficult to determine with certainty whether the browsing observed
on these willows was done by domestic sheep or elk.
Benefits to wolverine from selecting Alternative 1 would primarily be in improved conditions for
prey species in alpine cirque basins, and reduced disturbance in core wolverine habitat. However,
the benefits to wolverine would be less pronounced than for bighorn sheep or ptarmigan, and would
be limited to a few localized areas. In comparison to the very large average wolverine home range
size, the benefits of selecting Alternative 1 would probably be small.
Alternative 3
Selecting Alternative 3 would be generally beneficial for sensitive species, although less than under
Alternative 1, but more so than selecting Alternative 2. The improvements in habitat conditions for
sensitive species expected to occur over time under Alternative 3 are likely to be generally small and
limited to a few localized areas where habitat conditions are being affected by sheep grazing
activities under current management practices. For example, under current management practices
(Alternative 2) about 31% (40,159 acres) of the total acres of spruce-fir and alpine habitats on
Federal lands (130,866 acres) would be suitable for sheep grazing, compared to Alternative 3 where
about 21% (26,844 acres) would be suitable for sheep grazing.
79

Similar to Alternative 2, selecting Alternative 3 would have both positive and negative effects for
sensitive species. Selecting Alternative 3 would have beneficial effects for sensitive species,
compared to Alternative 2, because application of adaptive management strategies and project
design criteria should result in more rapid improvements in habitat conditions in some localized
areas where sheep grazing impacts are currently occurring. Also similar to Alternative 2, Alternative
3 would have negative effects for sensitive species, compared to Alternative 1, because a few
localized areas would continue to be affected by sheep grazing activities, such as near the
alpine/spruce-fir interface, moist alpine areas adjacent to riparian zones or wet meadows, and upland
willow stands in alpine basins.
Selecting Alternative 3 would be more beneficial for sensitive species than selecting Alternative 2,
but would be less beneficial than selecting Alternative 1. This is because improvement in habitat
conditions would probably occur over a longer time frame than under Alternative 1, but a shorter
time frame than Alternative 2 due to the application of adaptive management strategies and project
design criteria. In general, habitat conditions for sensitive species are expected to continue to
gradually improve in most areas under Alternative 3, but would continue to be impacted in a few
localized areas.
Compared to Alternative 2, the application of adaptive management strategies and project design
criteria under Alternative 3 should result in more rapid improvements in habitat conditions in some
localized areas where sheep grazing impacts are currently occurring because adaptive management
strategies would not be fully applied under Alternative 2. Although more rapid improvement in
habitat conditions for bighorn sheep, white-tailed ptarmigan and wolverine is expected under
Alternative 3 than under Alternative 2, improvements in habitat conditions as a result of the adaptive
management approach are likely to be too small to affect populations or the total amount of habitat
available for these species in the Silverton Landscape.
Selecting Alternative 3 would be much more beneficial for bighorn sheep than selecting Alternative
2, although less so than selecting Alternative 1. Alternative 3 would be less beneficial for bighorn
sheep than Alternative 1 because five allotments with areas of mapped overlap between domestic
sheep and bighorn sheep summer range (Picayne/Mineral Point, Engine Creek/Deer Creek, Eureka,
and Gladstone active allotments, and Flume vacant allotment) would remain open to sheep grazing
under Alternative 3. However, the potential for contact between domestic sheep and bighorn sheep
in these five allotments with areas of mapped overlap would be reduced from High to Moderate (4
active allotments) or Low (1 vacant allotment).
Alternative 3 would be much more beneficial for bighorn sheep than Alternative 2. This is because
three vacant allotments would remain available for sheep grazing under Alternative 2 (Little
Molas/West Needles Allotment, Needles Mountains Allotment, and Minnie Gulch Allotment) but
would be permanently closed to grazing under Alternative 3 (Figure 3-1). These three allotments
would have High Risk for contact if they were stocked with domestic sheep under Alternative 2, but
would have Low Risk for contact if closed under Alternative 3. For this reason, the potential for
physical contact between domestic sheep and bighorn sheep in these 3 allotments would be reduced
from High to Low, and the project’s desired condition for bighorn sheep would be met in these three
allotments.
As a result of closing these three allotments, under Alternative 3 the amount of mapped overlap
between areas suitable for domestic sheep and mapped bighorn sheep summer range in the Silverton
Landscape would be reduced from about 10,285 acres (Alternative 2) to about 1,756 acres
(Alternative 3). The areas of mapped overlap between bighorn sheep and domestic sheep ranges
where risk of physical contact between bighorn and domestic sheep is thought to be High would all
be reduced to Moderate Risk with the modification of allotment boundaries and the application of
80

project design criteria. In addition, the areas with mapped overlap between bighorn sheep summer
range and domestic sheep where the potential for contact between bighorn and domestic sheep is
thought to be low under Alternative 2 (Gladstone and Flume allotments) would remain low under
Alternative 3.
Under Alternative 3, the four active allotments with areas of mapped overlap between domestic
sheep and bighorn sheep summer range (Picayne/Mineral Point, Engine Creek/Deer Creek, Eureka,
and Gladstone allotments) would remain open to sheep grazing. However, the area with mapped
overlap would be significantly reduced under Alternative 3 (reduced by 83% compared to
Alternative 2. See Figures 1-5 and 3-1), and, the application of design criteria under Alternative 3
would, in combination, substantially reduce the potential for contact between domestic sheep and
bighorn sheep, thereby addressing one of the project’s need for change. Because the potential for
contact between domestic sheep and wild sheep would be reduced from High to Moderate in these
four active allotments, the project’s desired conditions for bighorn sheep would be met. The areas
with High Risk for physical contact between domestic sheep and bighorn sheep under Alternative 2
would all be reduced to Moderate Risk under Alternative 3.
The eighth and final area of mapped overlap between domestic sheep and bighorn sheep summer
range, in the southeast corner of the Flume Allotment, would remain a Low potential for contact
between domestic sheep and bighorn sheep due to habitat conditions and remaining vacant to
grazing. If this allotment were restocked in the future the potential for contact between domestic
sheep and wild sheep would be expected to remain Low because of its geographic location and
habitat conditions.
Similar to Alternative 2, selection of Alternative 3 would be expected to have some positive effects
on forage conditions for bighorn sheep. Selecting Alternative 3 would maintain the continued
gradual long term improvement in forage habitat conditions for bighorn sheep that has occurred for
the past 70+ years, but probably at a slower rate than would have occurred under Alternative 1.
Forage habitat conditions for bighorn sheep would be expected to continue their long term gradual
improvement under Alternative 3 because there has been a continued long term decline in the
number of domestic sheep grazed in the Silverton Landscape. There has been a 49% decline in the
number of domestic sheep grazed in the Silverton Landscape over the past 40 years, and a 95%
decline in the number of sheep grazing on the San Juan National Forest over the past 70 years. In
addition, the amount of the Silverton Landscape open to grazing under Alternative 3 would be
substantially reduced compared to Alternative 2. Therefore selecting Alternative 3 would reduce the
amount of area where forage overlap between domestic and bighorn sheep could potentially occur,
and as the number of domestic sheep on the landscape has declined, so too has the risk for direct
physical contact between domestic and bighorn sheep and the subsequent potential for disease
transmission has also declined.
Even if numbers of domestic sheep remain relatively stable over the next few (5+) years, a continued
gradual improvement in bighorn sheep forage conditions and white-tailed ptarmigan summer/fall
habitat areas would be expected under Alternative 3. This is because at current domestic sheep
stocking levels, the observed gradual improvement in alpine plant communities is expected to
continue, and the application of project design criteria and adaptive management practices would
further reduce affects from domestic sheep grazing.
Selecting Alternative 3 would be beneficial for white-tailed ptarmigan, although less beneficial than
selecting Alternative 1, but more beneficial than selecting Alternative 2. The few localized areas
currently affected by sheep grazing would continue to be affected, such as near the alpine/spruce-fir
interface, moist alpine areas adjacent to riparian zones and wet meadows, and upland willow stands
in alpine basins and on ridgelines. Although more rapid improvement in habitat conditions for
81

ptarmigan is expected under Alternative 3 than under Alternative 2, improvements due to adopting
the adaptive management approach are likely to be too small to affect ptarmigan populations or the
total amount of habitat available in the Silverton Landscape.
Selecting Alternative 3 would be beneficial for wolverine, although less beneficial than selecting
Alternative 1, but more beneficial than selecting Alternative 2. About 22% of alpine areas would be
suitable for sheep grazing under Alternative 3, which is a slight reduction from the 29% of alpine
areas suitable for sheep grazing under Alternative 2. Alpine areas provide the core of potential
wolverine habitat in the landscape, and include wolverine denning habitat. Although there appears
to be little difference between Alternative 2 and Alternative 3 in the amount of alpine area affected
by sheep grazing (about 7% reduction), the landscape is in the center of a region identified by the
CDOW and wolverine researchers as providing some of the best and most extensive potential
wolverine habitat in the state of Colorado. For this reason, even small changes in risk factors may
provide substantial benefits to a species that is documented to be highly sensitive to human
disturbance. However, it must be remembered that wolverine has not been confirmed to occur in the
landscape or anywhere in southwest Colorado in many decades. Given the lack of confirmed
wolverine occurrence in southwest Colorado, the risk of disturbance to individual animals from
sheep grazing activities is probably low.
82

Figure 3-1. Proposed Action - Bighorn Overlap
83

CUMULATIVE IMPACTS
Global warming is a contentious issue with a great deal of uncertainty about what likely outcomes
might be. However, there is little doubt that plants and animals found almost exclusively in the
alpine zone may be the first to decline or go extinct as a result of changes in global climate. Most
predictions about global climate change predict a gradual loss of alpine habitats as treeline moves
upward in response to a generally warming climate. For white-tailed ptarmigan, the effects of global
warming have the potential to have far greater consequences than the combined effects of grazing,
recreation, mining, and other human impacts. As such, global climate change may be the most
serious threat to long-term persistence of ptarmigan populations in the Silverton landscape.
More immediate and localized threats to alpine species, including ptarmigan, wolverine, and bighorn
sheep, include mining, water development, and motorized and non-motorized recreation. While
alpine ecosystems are hardy and resilient to natural environmental factors, they are particularly
vulnerable to human related disturbances and may require decades to recover. Although substantial
progress has been made in developing techniques to restore damaged alpine landscapes, this
technology is still not capable of restoring alpine plant communities to their pre-disturbance
condition (Hoffman 2006).
One of the largest impacts on the environment in this landscape has been past mining activities and
other activities associated with mining, such as road building (see watershed section above). One
hundred years of surface and subsurface mining operations have likely contributed to substantial
cumulative effects to habitat for sensitive. Some of the impacts of past mining activities have been
reduced or mitigated through natural re-vegetation of formerly impacted areas, and substantial
improvements in downstream water quality have been achieved as abandoned mines have been
reclaimed. Bighorn sheep populations around active mining areas were likely heavily impacted by
miners hunting for food before hunting restrictions were adopted in the early 1900’s.
The Colorado Division of Wildlife (CDOW) continues to manage the S33 Pole Mountain/Upper
Lake Fork bighorn sheep herd for possibility of providing hunting opportunities. Between 1982 and
1990 CDOW issued between 2 and 5 ram tags annually. S33 was closed to hunting between 1991
and 2005, then re-opened in 2006 with 3 ram tags issued annually since then. Hunting success rate
averages 30% for this unit (Diamond 2005). No ewe licenses have ever been issued for this herd.
The CDOW opened S71 for hunting for the first time in 2007 with 1 ram tag issued annually.
As the number of off-highway vehicles (OHV’s) continues to increase on most roads in the Silverton
Landscape, the potential for disturbance to bighorn sheep using areas that are adjacent to popular
OHV routes also continues to increase each year. The continual annual increase in OHV use
observed over the past 5-10 years is likely to continue for the foreseeable future. Increased
motorized disturbance to bighorn sheep in places such as Minnie Gulch may force animals away
from preferred foraging areas and into areas with lower quality forage or areas where animals are
more vulnerable to predation, leading to increased predation or mortality.
White-tailed ptarmigan populations in the southwest Colorado ore belt, roughly between Telluride,
Silverton and Lake City, including most of the Silverton Landscape, are thought to not be self
sustaining. The cause of low ptarmigan populations appears to be cadmium toxicity induced renal
failure and brittle bones that significantly reduces adult female over-winter survivorship (Larison et
al. 2000). Cadmium naturally occurs in high concentrations in the Colorado ore belt and is readily
mobilized by mining. Cadmium is taken up by willows and biomagnified in the buds which are the
primary fall and winter food source for ptarmigan (Braun et al. 1976). Larison et al. (2000) found
adult female survivorship in the southwest Colorado ore belt was reduced by more than half causing
highly skewed sex ratios and low productivity. They also documented high rates of immigration
84

(from nearby less contaminated populations) and the lowest breeding densities of any ptarmigan
population throughout the species’ range.
For this reason, protecting and maintaining fall and winter habitat for adult female ptarmigan is
likely to be a key factor in ensuring long-term population persistence in the landscape. Maintenance
and protection of fall and winter ptarmigan habitat is especially important given the high site fidelity
of wintering birds and the considerable numbers of adult females that are attracted from surrounding
breeding habitats to the few suitable wintering sites (Braun et al. 1976). Increasing motorized and
non-motorized recreation in preferred ptarmigan wintering areas along the Highway 550 corridor is
likely to be reducing ptarmigan winter habitat quality through increasing the extent of compacted
snow areas and increased disturbance to wintering birds. Ptarmigan populations in the Silverton
Landscape may be especially vulnerable to loss or degradation of fall and winter habitat given that
population densities in this area are lower than other parts of the species range and are likely not
self-sustaining (Larison et al. 2000).
Local bird watchers have reported consistent declines in numbers of white-tailed ptarmigan detected
over the past 5-10 years in known historic winter concentration areas around Silverton and along the
U.S. Highway 550 corridor. Most bird watchers attribute this perceived decline in the number of
wintering birds as likely caused by a coincidental substantial increase in snowmobile and nonmotorized
winter recreation in and around many historic ptarmigan wintering areas such as
Gladstone, Cement Creek, Little Molas Lake, Andrews Lake, and South Mineral Creek. Perceived
declines in the number of ptarmigan wintering around Andrews Lake, a non-motorized area, is
attributed to increased numbers of non-motorized winter recreationists that are often accompanied by
domestic dogs. Although many of these areas are within active sheep grazing allotments, no
evidence has been found that indicates grazing impacts are significantly affecting habitat capability
for ptarmigan in preferred wintering areas.
Other activities that continue to influence habitat capability for sensitive species in the Silverton
Landscape include development of private lands adjacent to public lands, increasing levels of jeep
and OHV traffic on most roads in the landscape, and mine reclamation activities that are gradually
improving water quality and downstream habitat capability. Influences that continue to affect
vegetation in the landscape and therefore affect habitat capability for sensitive species include
ongoing fire suppression, personal use firewood harvesting of standing dead trees for use as primary
home heating purposes, and natural events such as wild fire, forest insect and disease outbreaks,
wind throw events, and avalanches. All these activities have contributed to changes in the
composition, structure, and function of forested habitats in the landscape, and habitat for sensitive
species.
As the number of off-highway vehicles (OHV’s) continues to increase on most roads in the Silverton
Landscape, the potential for disturbance to wolverine in areas adjacent to popular OHV routes also
continues to increase each year. The continual annual increase in OHV use observed over the past 5-
10 years in the Silverton Landscape is likely to continue for the foreseeable future. Wolverines are
known to be very sensitive to human disturbance (Banci 1994). An aerial habitat inventory by the
Colorado Division of Wildlife and wolverine researcher Jeff Copeland determined that the central
San Juan Mountains near Silverton appeared to provide some of the highest quality potential
wolverine habitat in the state of Colorado (S. Wait pers. comm.). There are nearly annual reports of
wolverine sightings, all unconfirmed, from the central San Juan Mountains, mostly between
Silverton, Ouray and Lake City (S. Wait pers. comm.). As motorized traffic and non-motorized
recreation in formerly remote alpine areas increases, habitat capability for wolverine would be
expected to continue to decline.
85

Wildlife – Management Indicator Species_____________
The 1983 San Juan National Forest Land and Resource Management Plan (SJNF 1992) establishes
management direction for Management Indicator Species (MIS). The BLM has no policies or
direction to address MIS so the following discussion will address only those species listed in the
Forest Plan, and only where those species occur on National Forest System lands. A wildlife review
for MIS was written to analyze the impacts of alternatives to management indicator species,
following agency and Forest Plan direction, and can be found in the project record (Schultz 2009c).
The Forest Plan establishes management direction for maintaining healthy populations of wildlife
and fish species. Due to the large number of species that occupy National Forest lands, a subset of
species is identified for analysis purposes that are intended to represent the full range of species.
This subset is collectively referred to as Management Indicator Species (MIS). The Forest Plan
establishes goals, objectives, standards, guidelines, and monitoring requirements that are specific to
MIS. Each action proposed by the agency is analyzed in a manner that discloses its effects to MIS
and evaluates its consistency with the management direction contained in the Forest Plan. The
analysis then determines what effect project-level impacts might have on Forest-level population and
habitat trends for each MIS analyzed.
This analysis is based on the best available science such as the most recent Forest-wide habitat and
individual MIS assessments, expert professional opinions, and site-specific field review of the
analysis area. These assessments explain the reasons for MIS selection in the Forest Plan, and
contain information on the species life history, conservation status, distribution, abundance on Forest
and each Ranger District, and population and habitat trends.
This MIS analysis complies with the 2008 Planning Rule, 36 CFR Part 219. Management indicator
species monitoring is not discussed in the final rule. The 1982 rule is not in effect (sec.
219.14(b)(4)). No obligations remain from that regulation (including MIS), except those that are
specifically in a Forest Plan. Section 219.14 (b) (4) states, “For units with plans developed,
amended, or revised using the provisions of the planning rule in effect prior to November 9, 2000
(See 36 CFR parts 200 to 299, Revised as of July 1, 2000), that rule is without effect. No obligations
remain from that regulation, except those that are specifically in the plan.”
This analysis meets the current MIS analysis requirements in the San Juan National Forest Land and
Resource Management Plan. The current Forest Plan does not rely solely on gathering/using
quantitative population data, but specifically allows for the use of a variety of species information
and data sources that can be used to conduct the MIS analysis. Table IV-1 on page IV-4 of the
Forest Plan lists a variety of acceptable analysis data sources for monitoring populations and habitat
trends of MIS, such as, population estimates by State Wildlife agencies, professional judgment of
USFS Wildlife Biologists, habitat inventory assessments, resource information system data, and
activity/program reviews. All MIS identified in the Forest Plan and reasons for their selection are
considered during initial project screening. A detailed analysis was then conducted for those MIS
that may be affected by the proposed action (Table 1). The analysis describes how the proposed
action will affect Forest-wide habitat and population trends (direct and indirect effects section,
below).
A detailed analysis is intended to disclose the potential effects of the action on MIS and their
habitats in a manner that identifies the relationship between the action being considered and the
long-term viability of the MIS. For this analysis, the “effects of the action” include the direct and
indirect effects to the species caused by the proposed project, and are effects that are reasonably
certain to occur. “Reasonably certain to occur” requires existence of clear and convincing
information that establishes an effect to the MIS will be caused by the proposed action. This
86

equires that a cause and effect relationship be established that is not merely speculative or based on
remote possibilities. Principals of population ecology using the concept of species limiting factors
as they relate to reproduction, growth, mortality rates, and distribution of MIS are applied whenever
possible.
Most MIS species analyzed in detail have either been observed or reported on NFS lands in the
Silverton Landscape. Additionally, most MIS species have habitat that is well distributed across the
San Juan National Forest, with the exception of Colorado River cutthroat trout and Uncompahgre
fritillary butterfly. It should also be noted that within and adjacent to NFS lands in the Silverton
Landscape there are large amounts of habitat in similar condition, and this habitat is well distributed
across the landscape and connected to the larger National Forest administrative unit. The Silverton
Landscape does not provide unique or isolated habitats within which discrete populations are
restricted. Aside from Canada lynx and southwestern willow flycatcher, most MIS are not species at
risk nor are they species that are trending towards protected status and are well distributed across the
San Juan National Forest.
For some species, such as mule deer and elk, there appears to be no relationship between habitat
trends and population trends, with population trends regulated by State hunting season structures.
For other species, such as Canada lynx and river otter, population trends are dependant primarily on
the results of Colorado Division of Wildlife reintroduction efforts, rather than the amount or
distribution of habitat on National Forest System lands. For other species, such as deer mouse,
populations are highly variable and regulated primarily by local annual weather patterns, rather than
the amount or distribution of habitat. Again, MIS regulations do not apply to non-National Forest
System lands and thus this analysis will be limited solely to those species and acres of habitat that
occur on National Forest System lands.
AFFECTED ENVIRONMENT
There are 23 species identified as MIS in the SJNF Forest Plan. Some species are not present in the
Silverton Landscape due to the absence of suitable habitat, or, suitable habitat is present in the
landscape but the proposed action (domestic sheep grazing) will not affect the species or its key
habitat components. Table C-3 (Appendix C) provides rationale for why some MIS species were
brought forward for detailed project analysis and other species were not. A total of five species have
habitat present in the Silverton Landscape and may be affected by domestic sheep grazing (Table 3-
1, below). The five species brought forward for detailed analysis for this range analysis project
include: Canada lynx, elk, mule deer, green-tailed towhee, and mountain bluebird. Affects of
domestic sheep grazing to federally listed species (Canada lynx) was also discussed in the project’s
Biological Assessment. Affects to Forest Service designated Sensitive Species were also discussed
in the project’s Biological Evaluation.
Existing habitat for each MIS was determined by the use of a computer mapping model using
vegetative information described in Forest-wide MIS Assessments on National Forest System lands.
Habitat modeling was conducted using habitat structural stage matrices described by Towry (1984).
In addition, information on species’ distribution across the Forest, professional judgment of FS
wildlife biologists, coordination with CDOW biologists, coordination with the U.S. Fish and
Wildlife Service, and field reconnaissance of the project area was also used.
A brief description of suitable habitat for each MIS species brought forward for detailed project
analysis, their likely period of use, and Forest-wide habitat and population trend estimates for each
of these MIS species are provided in the Wildlife Review (Schultz 2009c) in the project record.
More detailed information about species natural history requirements, distribution, and habitat and
population trends is on file at the Columbine Ranger District Office located in Bayfield, Colorado
87

and it will not be discussed in detail here.
ENVIRONMENTAL CONSEQUENCES
The Wildlife Review analyzed the impacts of alternatives to MIS. Table 3-1 summarizes the
impacts to Forest-wide habitat and population trends that would result from each of the proposed
alternatives. Details of the analysis leading to the summary can be found in the project record
(Schultz 2009c).
MIS
Forestwide
Habitat
Trend
Canada lynx Stable
Elk (Cervus elaphus)
Green-tailed towhee
(Pipilo chlorurus)
Mountain bluebird
(Sialia currucoides)
Mule deer (Odocoileus
hemionus)
Stable
downward
Stable
upward
Table 3-1. Forest-wide habitat and population trends for MIS.
Forest-wide
Population
Trend
Upward due
to
reintroduction
efforts by
Colorado
Division of
Wildlife
Stable
Stable Stable
Downward Stable
Forest-wide
Habitat
Habitat in Landscape
Suitable for Sheep
Grazing under
Current Management
(Alternative 2)
Habitat in Landscape
Suitable for Sheep
Grazing under Preferred
Alternative (Alternative
3)
992,264 19,199 (2%) 10,446 (1%)
Forage – 568,898
Cover – 1,002,716
Winter – 471,234
Forage - 9,102 (2%)
Cover - 15,738 (2%)
Winter - 0
Forage – 4,644 (

MIS
Existing NFS Habitat
Acres in Silverton
Landscape
Table 3-2. Acres of habitat affected for MIS.
Acres of Habitat Affected by
Sheep Grazing Under Current
Management (Alternative 2)
Acres of Habitat Affected by
Sheep Grazing Under Proposed
Action (Alternative 3)
Total Acres Suitable Acres Total Acres Suitable Acres
Canada lynx 65,386 64,048 (98%) 19,199 (29%) 23,071 (35%) 10,446 (16%)
Elk and Mule Deer
Forage
34,535 33,779 (98%) 9,102 (26%) 13,278 (38%) 4,644 (13%)
Elk and Mule Deer
cover
51,955 50,607 (97%) 15,738 (30%) 17,426 (34%) 7,981 (15%)
Elk and Mule Deer
winter range
0 0 0 0 0
Green-tailed towhee 10,838 10,563 (97%) 1,525 (14%) 3,018 (28%) 576 (5%)
Mountain bluebird
foraging
10,164 9,925 (98%) 3,921 (39%) 5,517 (54%) 2,270 (22%)
Mountain bluebird
nesting
20,737 20,445 (99%) 5,258 (25%) 4,573 (22%) 1,612 (8%)
Alternative 1 –No Action
Alternative 1, the No Action Alternative, would be wholly beneficial for all MIS on National Forest
System Lands because domestic sheep grazing would not be re-authorized in the Silverton
Landscape. There would be no impact on Forest-wide habitat trends or population trends from
selecting Alternative 1. There would be no potential impacts from sheep grazing activities to key
habitat components for MIS. Selection of Alternative 1 has the potential to provide direct benefits to
MIS but the degree of benefit would probably be small in any given year and limited in scale on the
landscape to those small areas affected by domestic sheep grazing and not meeting desired
conditions under current management. Benefits to MIS from selecting Alternative 1 would probably
be long term (> 10 years).
Benefits to MIS from selecting Alternative 1 would probably be most pronounced for elk in alpine
basins, followed by Canada lynx at or near the spruce-fir forest/alpine interface. Benefits to mule
deer would probably be less pronounced than for elk. Benefits to mountain bluebird, and greentailed
towhee would likely be slight and limited to a few localized areas. Benefits to elk forage and
mountain bluebird foraging areas would come from gradual, long term improvements in the
condition of moist alpine areas adjacent to riparian zones or wet meadows. These potential
improvements however would be limited to a few localized areas where current utilization levels are
high and impacts to soil and vegetation have historically occurred or are continuing to occur.
Alternative 2
Selection of Alternative 2 is expected to result in continued improvement in habitat conditions for
MIS, but at a slower rate than would have occurred under Alternative 1. Habitat conditions for MIS
are expected to improve under Alternative 2 because there has been a continued decline in the
number of domestic sheep grazed in the Silverton Landscape over the past 40 years. Numbers of
domestic sheep grazing in the Silverton Landscape have dropped about 51% from a high of about
16,000 animals in the 1960’s to about 8,230 currently. In addition, numbers of sheep grazing on the
San Juan National Forest have dropped about 95% from a high of about 216,600 animals in the
1930’s to about 10,800 currently. As numbers of sheep have declined in the landscape, habitat
conditions for MIS, especially those MIS that forage in alpine areas in mid to late summer, have had
a long term and gradual improvement in foraging habitat conditions. Gradual improvements in
habitat conditions for MIS are expected to continue for some time in the future even if numbers of
sheep remain relatively stable over the next few (5+) years because alpine plants have a relatively
short growing season and recovery processes are slower than in other lower elevation habitat types.
89

Selecting Alternative 2 would have both positive and negative effects for MIS. Selecting Alternative
2 would have beneficial effects for MIS because current sheep management practices would
maintain current habitat capability for MIS across much of the landscape. Alternative 2 would also
have negative effects for MIS, compared to Alternative 1, because a few localized areas would
continue to be affected by sheep grazing activities, such as near the alpine/spruce-fir interface.
Selecting Alternative 2 would be generally beneficial for MIS, but less so than selecting Alternative
1 because improvement in habitat conditions would probably occur over a longer time frame than
under Alternative 1. In general, habitat conditions are expected to continue to gradually improve in
most areas under Alternative 2 but habitat conditions for MIS would continue to be impacted in a
few localized areas.
Under current management, an average of about 27% of the habitat in the landscape for these five
MIS is considered suitable for sheep grazing. Displayed another way, about ¾ of the habitat for
these 5 species in the Silverton Landscape is considered unsuitable for sheep grazing and therefore
not likely to be significantly affected by the selection of any project alternative. Only about ¼ of the
habitat in the landscape for these 5 species might be affected by sheep grazing. For these 5 species,
the amount of habitat suitable for sheep grazing under Alternative 2 represents about 2% of their
habitat Forest-wide. For this reason, selection of Alternative 2 would not cause measurable changes
to Forest-wide habitat trends or population trends for any of these 5 species.
Population trends for elk and mule deer are controlled by annual hunter harvest and do not appear to
be correlated with the amount of available habitat on the Forest. Canada lynx populations in the San
Juan Mountains have been primarily influenced by years of releases of translocated animals by the
Colorado Division of Wildlife. The slight habitat improvements resulting from changes in sheep
grazing practices in the Silverton Landscape are unlikely to cause measurable changes in the amount
of available lynx habitat or lynx populations at the scale of the entire San Juan National Forest.
Changes in habitat capability for mountain bluebird and green-tailed towhee are likely to be very
small in comparison to the relatively large amounts of habitat available for these species at the
Forest-wide scale. Both species are widespread across the Forest and population trends and habitat
trends are stable to slightly upward. In addition, impacts of sheep grazing to foraging and nesting
habitat for these species is limited to a few localized areas and thus is unlikely to affect more than a
few individuals and would not have a measurable impact on habitat or populations trends at the
Forest-wide scale.
Alternative 3
For all MIS, Alternative 3 is expected to be less impacting than Alternative 2 due to specific project
design criteria and adaptive management actions designed to best meet or move towards the desired
objectives conditions. Alternative 2 will generally maintain current rangeland conditions, thereby
providing fewer benefits to wildlife and habitats or resulting in slower development of desired
conditions than Alternative 3. Both action alternatives may affect individuals but are unlikely to
affect local populations, and have the potential to cause minor changes in species abundance.
Neither of the action alternatives is expected to result in negative consequences to MIS populations
from the standpoint of affecting viability at the Forest-level.
Selecting Alternative 3 would be generally beneficial for MIS, although less than under Alternative
1 but more than selecting Alternative 2. The improvements in habitat conditions for MIS expected
to occur over time under Alternative 3, compared to Alternative 2 are likely to be generally small
and limited to a few localized areas where habitat conditions are being affected by sheep grazing
activities under current management practices. For example, under Alternative 3 there would be a
31% reduction in the acres of alpine and spruce-fir habitats suitable for domestic sheep grazing
(about 27,700 acres), compared to Alternative 2 (about 40,100 acres). Under Alternative 3 only 16%
90

of the lynx habitat in the Silverton Landscape would occur in areas suitable for livestock grazing,
compared to 29% of lynx habitat under Alternative 2.
Similar to Alternative 2, selecting Alternative 3 would have both positive and negative effects for
MIS. Selecting Alternative 3 would have beneficial effects for MIS, compared to Alternative 2,
because application of adaptive management strategies and project design criteria should result in
more rapid improvements in habitat conditions in some localized areas where sheep grazing impacts
are currently occurring. Also similar to Alternative 2, Alternative 3 would have negative effects for
MIS, compared to Alternative 1, because a few localized areas would continue to be affected by
sheep grazing activities, such as near the alpine/spruce-fir interface. Selecting Alternative 3 would
be generally beneficial for MIS, more so than selecting Alternative 2, but less than selecting
Alternative 1, because improvement in habitat conditions would probably occur in a shorter time
frame than Alternative 2, but over a longer time frame than under Alternative 1. In general, habitat
conditions are expected to continue to gradually improve in most areas under Alternative 3 but
habitat conditions for MIS would continue to be impacted in a few localized areas.
Compared to Alternative 2, the application of adaptive management strategies and project design
criteria under Alternative 3 should result in more rapid improvements in habitat conditions in some
localized areas where sheep grazing impacts are currently occurring. This is because adaptive
management strategies would not be applied under Alternative 2. Although more rapid improvement
in habitat conditions for MIS is expected under Alternative 3 than under Alternative 2,
improvements in habitat conditions as a result of the adaptive management approach are likely to be
too small to affect populations or the total amount of habitat available in the Silverton Landscape.
Under Alternative 3, an average of about 13% of habitat in the landscape for these five MIS is
considered suitable for sheep grazing, compared to about 27% under Alternative 2. This is an
average of less than 1% of habitat for these species Forest-wide, compared to about 2% under
Alternative 2. Because selection of Alternative 3 would affect only a very small amount of habitat
for these species Forest-wide (< 1%), selection of Alternative 3 would not cause measurable changes
to Forest-wide habitat trends or population trends for any MIS. Because the amount of MIS habitat
affected by sheep grazing under Alternative 3 would be about half the amount of MIS habitat
affected by sheep grazing under Alternative 2, selection of Alternative 3 would be more beneficial
for MIS species than selection of Alternative 2.
CUMULATIVE IMPACTS
One of the largest impacts on the environment in this landscape has been past mining activities and
other activities associated with mining, such as road building (see watershed section above). One
Hundred years of surface and subsurface mining operations have likely contributed to substantial
cumulative effects to habitat for MIS that use riparian and wetland habitats. Some of the impacts of
past mining activities have been reduced or mitigated through natural re-vegetation of formerly
impacted areas, and substantial improvements in downstream water quality have been achieved as
abandoned mines have been reclaimed.
Other activities that continue to influence habitat capability for MIS include development of private
lands adjacent to public lands, increasing levels of jeep and OHV traffic on most roads in the
landscape, and mine reclamation activities that are gradually improving water quality and habitat
capability for MIS using habitats down stream. Influences that continue to affect vegetation in the
landscape and therefore affect habitat capability for MIS include ongoing fire suppression, personal
use firewood harvesting of standing dead trees for use as primary home heating purposes, and
natural events such as wild fire, insect and disease outbreaks, wind throw events, and avalanches.
All these activities have contributed to changes in the composition, structure, and function of habitat
91

for MIS in the landscape.
Wildlife – Migratory Birds__________________________
AFFECTED ENVIRONMENT
An Executive Order titled responsibilities of federal agencies to protect migratory birds was enacted
in 2001 (EO 13186). The order requires federal agencies to consider the effect of land management
projects on migratory birds, particularly those species for which there may be conservation concern.
Agencies are to “restore and enhance the habitat of migratory birds, as practicable” and to “evaluate
the effects of actions and agency plans on migratory birds, with emphasis on species of concern.”
There is conservation concern for some species of migratory birds due to naturally small ranges, loss
of habitat, observed population declines, and other factors.
This analysis focuses on migratory bird species that have been identified as candidates for
conservation priority by at least one of the following lists: the Endangered Species Act (addressed in
the Biological Assessment), BLM’s Colorado State Sensitive Species List (addressed in the
Biological Evaluation), the Forest Service Rocky Mountain Regional Forester’s Sensitive Species
List (addressed in the Biological Evaluation), the U.S. Fish and Wildlife Service’s Birds of
Conservation Concern list (U.S. Fish and Wildlife Service 2002), the Colorado Division of Wildlife’s
Colorado Listing of Endangered, Threatened and Wildlife Species of Special Concern (CDOW
2007). Colorado’s Comprehensive Wildlife Conservation Strategy (CDOW 2006) was also
reviewed.
This section reviews likely potential effects of the project alternatives on migratory bird species for
which there may be conservation concern and that are thought likely to occur in the Silverton
Landscape. More detailed information on the habitat requirements, status, distribution, abundance
and key habitat components of most species is on file at the Columbine Public Lands Center office
in Bayfield, Colorado and will not be reviewed here.
Of the 55 bird species of concern identified on one of these lists (Appendix C), 27 species have
breeding and/or non-breeding habitats in the Silverton Landscape. Of the 27 species that are likely
to occur in the landscape, 19 species are likely to occur only during the breeding season, and 8
species occur in the analysis area year round. The 27 bird species of concern that are likely to occur
in the landscape are grouped into seven general analysis categories based on life history
requirements or the habitats where the species is most commonly found in the landscape. The seven
general analysis categories are alpine tundra (American pipit, brown-capped rosy finch, and whitetailed
ptarmigan), cavity dependant (boreal owl, mountain bluebird, and violet-green swallow),
cavity constructors (three-toed woodpecker, hairy woodpecker, red-naped sapsucker, and
Williamson’s sapsucker), cliff nesters (golden eagle, peregrine falcon, and prairie falcon), mixedconifer
(broad-tailed hummingbird, dusky grouse, flammulated owl, and Merriam’s turkey),
riparian/wetlands (American dipper, black swift, cordilleran flycatcher, lazuli bunting,
MacGillivray’s warbler, mallard, and Wilson’s warbler), and spruce-fir (Hammond’s flycatcher,
northern goshawk, and olive-sided flycatcher).
It should be noted that some birds (such as Williamson’s sapsucker and northern goshawk) nest and
forage in a wide variety of habitat types across the landscape. Other species (such as golden eagle)
nest in one habitat type (vertical cliff faces) but forage in another quite different habitat type (alpine
tundra). Also, some species that breed in the landscape (such as olive-sided flycatcher and violetgreen
swallow) leave in late summer for other, generally remote, wintering areas (Central and South
America). Other species however, are found in the landscape year round (such as white-tailed
ptarmigan and brown-capped rosy finch).
92

Spruce-fir and alpine tundra, together, comprise 76% of the landscape, 88% of the acres suitable for
domestic sheep grazing in the landscape under Alternative 3, and 83% of the acres under Alternative
2.
ENVIRONMENTAL CONSEQUENCES
For most bird analysis groups (4 of 7 groups) and about half the bird species (13 of 27 species),
domestic sheep grazing activities have little impact on their key habitat components and thus there is
little difference in potential effects between the three project Alternatives. The four bird analysis
groups unlikely to be affected by domestic sheep grazing activities are the cavity constructor group,
cavity dependant group, cliff nesters, and mixed-conifer group. Domestic sheep prefer to quickly
pass through forested habitats on their way to and from their preferred alpine grazing areas.
Therefore, grazing impacts are generally light in closed canopy forest stands and impacts to standing
trees are rare.
The four species of woodpeckers in the cavity constructor group rarely forage on the ground, and
domestic sheep grazing has little affect on the standing dead and diseased trees that provide the key
habitat component for this group. Although a few snags may be cut for use as firewood by the
herders, most sheep herder camps are located well above timberline and are moved frequently,
leading to widely dispersed cutting areas. For these reasons, activities associated with domestic
sheep grazing have little effect on habitat capability for the cavity constructor group. For the same
reasons, sheep grazing also has little effect on the cavity dependant group. The mountain bluebird
however, nests in cavities located near the edges of forest stands and forages for large insects on the
ground in nearby tundra or subalpine meadows. Bluebird foraging habitat and prey abundance can
be reduced by intensive domestic sheep grazing near the edges of forested stands. For the most part
however, sheep grazing activities are well removed from the edges of forested stands and therefore
probably have little effect on bluebird foraging habitat beyond a few widely scattered localized
areas.
The cliff nester group is probably not affected by domestic sheep grazing activities. They nest in
locations inaccessible to sheep and forage across wide areas roughly equivalent to entire allotments.
Given the generally good upland conditions across most of the Silverton Landscape, it is unlikely
that effects of domestic sheep grazing on the primary prey species of these three cliff nesting raptors
is at a level that would affect productivity or survivorship of young.
The mixed-conifer group is unlikely to be significantly affected by domestic sheep grazing activities
because sheep spend little time in this habitat type, preferring instead to pass rapidly through these
typically dense stands on their way too and from preferred alpine foraging areas. Most turkey and
dusky grouse nests have hatched before domestic sheep arrive thus trampling by sheep is unlikely to
pose a significant risk to nests of these two species. Sheep forage utilization rates are typically low
in these stands because sheep generally pass rapidly through them. Grasses and forbs then have the
remainder of the growing season to re-grow and set seed. Therefore, the impact of sheep grazing on
foraging habitats for the mixed-conifer bird group is typically low and short in duration and unlikely
to affect overall habitat capability.
Alternative 1 –No Action
Alternative 1, the no action alternative, would be wholly beneficial for migratory birds of
conservation concern because domestic sheep grazing would not be re-authorized in the Silverton
Landscape. There would be no potential impacts from sheep grazing activities to birds in the seven
analysis groups. The analysis groups that would benefit most from selecting Alternative 1 are the
alpine tundra group (3 species), riparian/wetlands group (7 species), and spruce-fir group (3 species).
93

The alpine tundra group would benefit most of all the analysis groups from selecting Alternative 1.
Selection of Alternative 1 has the potential to provide direct benefits to two of the three species in
the alpine tundra analysis group (American pipit and white-tailed ptarmigan). The third species in
this group is less likely to have substantial benefit from selecting Alternative 1 because it is less
likely to be directly affected by sheep grazing activities.
Alternative 2
Selecting Alternative 2 would be substantially less beneficial for birds of conservation concern than
selecting Alternative 1, and somewhat less beneficial than selecting Alternative 3, especially for
alpine species. For all bird species of conservation concern, selecting Alternative 2 would generally
maintain current habitat conditions, and for some species, likely result in a gradual long term
improvement in habitat conditions.
Habitat conditions for some bird species is expected to continue to gradually improve under
Alternative 2 because there has been a continued decline in the number of domestic sheep grazed in
the Silverton Landscape. Numbers of domestic sheep grazing in the Silverton Landscape have
dropped about 67% from a high of about 16,000 animals in the 1960’s to about 5,300 currently. In
addition, numbers of sheep grazing on the San Juan National Forest have dropped about 95% from a
high of about 216,600 animals in the 1930’s to about 10,800 currently (SJNF 2009).
Alpine tundra represents about 38% of the habitat in the Silverton Landscape, and about 29% of the
alpine tundra habitat in the landscape is suitable for sheep grazing under current management.
Sheep obtain most of their forage and spend most of their time in the alpine zone. Alpine habitats are
also potentially the most sensitive habitats to livestock grazing because of their very short annual
growing seasons, harsh environmental conditions, frequently shallow soils, and often long time span
for vegetation recovery. The three bird species whose primary habitats occur in the alpine zone
therefore have the potential to be significantly affected by domestic sheep grazing impacts.
Of the three bird species in the alpine tundra analysis group, two (American pipit and white-tailed
ptarmigan) can be directly affected by domestic sheep grazing because they nest on the ground and
forage in areas used by grazing sheep. These two species can be directly affected through the loss of
cover at nest sites, nest trampling by grazing animals, and reduced quality of foraging habitat due to
grazing reducing plant material upon which their insect prey depends (Hoffman 2006, and Versaw
1998). The third species in the alpine analysis group, brown-capped rosy finch, is less likely to be
directly affected by grazing sheep because nests are located in rock cliff crevices and adults forage
mainly on or near snow fields, areas that are actively avoided by domestic sheep (Nelson 1998). For
these three alpine bird species of concern, selecting Alternative 2 would be least beneficial of the
three project alternatives but would result in maintaining current habitat capability or result in a
gradual long term improvement in habitat capability.
Of the seven species in the riparian/wetland group, (American dipper, black swift, cordilleran
flycatcher, and mallard) are unlikely to be affected by sheep grazing. These species usually nest in
places that are inaccessible to sheep such as in dense cover (mallard), adjacent to waterfalls (black
swift), on rock walls overhanging streams (American dipper), and in dirt cut banks (cordilleran
flycatcher). These species also typically forage in areas not frequented by sheep such as in standing
water (mallard) high above the surrounding mountain peaks (black swift), on the floor of rapidly
flowing streams (American dipper), or in the overhead forest canopy (cordilleran flycatcher). For
these reasons, selecting Alternative 2 would have little impact on habitat capability for these four
species in the riparian/wetland analysis group.
The remaining three species in the riparian/wetland group (lazuli bunting, MacGillivray’s warbler,
and Wilson’s warbler) are associated with dense willow and riparian shrublands. Field monitoring
94

in the Silverton Landscape found that browsing appears to be affecting willows in some small and
localized areas. Sheep readily browse on willows in riparian and wetland areas but most of the
willow riparian areas across the landscape are in upper mid-seral successional stage, or are in an
upward trend and therefore are meeting land management plan direction for riparian condition. The
remaining three bird species in the riparian/wetland analysis group are also commonly found in tall
willows on mountain side slopes associated with springs or sites with a heavy snowpack that extends
late into the summer. Some heavy browsing was observed on willows in a few localized areas,
however it was difficult to determine with certainty whether the primary cause of this browsing was
domestic sheep or elk. Sheep trailing was also evident in some riparian and willow dominated areas
but current plant species composition and distribution are likely similar to conditions found during
the reference period. All of the riparian monitoring samples on both BLM and FS lands met the
project’s desired conditions. Therefore, overall, the effects of sheep grazing and trailing in
riparian/wetland areas appears to be small and/or limited to localized areas. For these reasons,
selection of Alternative 2 would be beneficial to birds in the riparian/wetland analysis group, but the
benefits would probably be small and localized in scale but continue to improve over the long term.
The benefits for these species of selecting Alternative 2 would however be less than for selecting
Alternative 1.
The spruce-fir analysis group is unlikely to be significantly affected by domestic sheep grazing
activities because sheep spend little time in this habitat type, preferring instead to pass rapidly
through closed canopy forests on their way too and from preferred alpine foraging areas. In general,
sheep spend little time in these areas because of the lack of forage under closed canopy conifer
forests. Usually, sheep grazing impacts in closed canopy spruce-fir forests are small in scale and
limited in scope as animals rest near the edges of parks or alpine zones.
Spruce-fir forests make up about 37% of the Silverton Landscape and 43% of the area currently
suitable for sheep grazing in the landscape. Spruce-fir forests are also in close proximity to some
preferred sheep grazing areas and therefore some small and localized areas of grazing impacts were
observed. The three species in the spruce-fir analysis group (Hammond’s flycatcher, northern
goshawk, and olive-sided flycatcher) are unlikely to be significantly affected by sheep grazing
activities because they prefer to nest and forage in overstory trees that are generally not affected by
sheep grazing. However, in areas where localized grazing impacts are occurring, there may be small
reductions in the abundance or diversity of potential insect prey or small birds and mammals that
provide prey for northern goshawk. For this reason, selection of Alternative 2 could provide small
and localized benefits to birds in the spruce-fir analysis group but this benefit would probably be less
than for selecting Alternative 1.
Alternative 3
Selection of Alternative 3 is likely to result in some improvement in habitat conditions for bird
species of conservation concern in the alpine, riparian/wetland, and spruce-fir analysis groups. The
improvements however are likely to be generally small and limited to localized areas. Improvement
in habitat conditions for birds in these analysis groups are likely to be considerably less under
Alternative 3 than under Alternative 1, but somewhat more than under alternative 2. Under
Alternative 3 there would be a 31% reduction in the acres of alpine and spruce-fir habitats suitable
for domestic sheep grazing (about 27,700 acres), compared to Alternative 2 (about 40,100 acres).
Compared to Alternative 2, the application of adaptive management strategies and project design
criteria under Alternative 3 should result in more rapid improvement in habitat conditions for these
three bird analysis groups because adaptive management strategies are not being fully applied under
current grazing management practices. Although more rapid improvement in habitat conditions is
expected under Alternative 3 than under Alternative 2, improvements in habitat conditions for bird
95

species of conservation concern as a result of the adaptive management approach are likely to be too
small to affect populations or the total amount of habitat available in the Silverton Landscape.
CUMULATIVE IMPACTS
Selection of Alternative 3 is likely to result in some improvement in habitat conditions for bird
species of conservation concern in the alpine, riparian/wetland, and spruce-fir analysis groups. The
improvements however are likely to be generally small and limited to localized areas. Improvement
in habitat conditions for birds in these analysis groups are likely to be considerably less under
Alternative 3 than under Alternative 1, but somewhat more than under alternative 2. Under
Alternative 3 there would be a 31% reduction in the acres of alpine and spruce-fir habitats suitable
for domestic sheep grazing (about 27,700 acres), compared to Alternative 2 (about 40,100 acres).
Compared to Alternative 2, the application of adaptive management strategies and project design
criteria under Alternative 3 should result in more rapid improvement in habitat conditions for these
three bird analysis groups because adaptive management strategies are not being fully applied under
current grazing management practices. Although more rapid improvement in habitat conditions is
expected under Alternative 3 than under Alternative 2, improvements in habitat conditions for bird
species of conservation concern as a result of the adaptive management approach are likely to be too
small to affect populations or the total amount of habitat available in the Silverton Landscape.
Socioeconomics _________________________________
AFFECTED ENVIRONMENT
The social and economic implications of forest resource management are of interest to local
residents surrounding federal lands, Forest and BLM users, and other people throughout the area.
The project area contains approximately 171,600 acres in San Juan County, 23,000 acres in La Plata
County, and approximately 500 acres in Ouray County.
The current five permittees, along with their herders, live in Montrose County. Although the land
covered by the grazing permits are mostly within San Juan County, there is little economic impact
on that county. The communities most likely to be impacted are those in which the permittees and/or
their primary business managers live, pay taxes, and do business. Those communities are Montrose
and Olathe, which are located within Montrose County; therefore only demographic information and
statistics for Montrose County will be used.
Much of the following information is taken from A SocioEconomic Profile of Montrose County,
Colorado (EPS, 2009) and from US Census Bureau 2000 data .
Geography: Montrose County encompasses 2,2,43 square miles of land area, making it the 16 th
largest county in the state of Colorado. The federal government owns approximately 70% of the
land in Montrose County.
Demographic Information: Montrose County is located in the southwestern region of the state, with
its population center being the city of Montrose. Montrose County has around 40,000 residents,
making it the 17 th most populated county in the state, with a population density of 18 inhabitants per
square mile. The population growth rate for Montrose County has been 2% since 1970, which is
slower than for the state of Colorado as a whole, but faster than the nation.
Employment and Income: The majority of employment in Montrose County is in the service
industry, followed by government, construction, and then agricultural jobs. Per-capita income for
people in Montrose County is slightly lower than the state-wide and national average. The
percentage of county residents living below the poverty line in 1999 was 12.6%. Farm employment,
96

which includes ranching as well as farming, provided 6% of the all county jobs in 2006, but only 1%
on the personal income, and is a shrinking sector of total jobs.
Social Factors: Montrose County is fairly homogeneous ethnically and racially. Whites make up
about 82% of the population, with Hispanic or Latinos contributing about 15%, American Indians
about 2%, and about 5% other races (percentages add up to more than 100% because some
individuals report more than one race). The county is considered average for economic
specialization, with in over-reliance on construction, agriculture, forestry, fishing and hunting, and
an under-reliance on manufacturing and finance industries.
The importance of the ranching sector is highlighted more as a social benefit than as an economic
base to the area as a whole. It is an important part of the people’s heritage in Montrose County.
Ranching operations in the area often operate at a loss or close to the margin and their profitability
can be substantially affected by a variation of market conditions. If access to federal lands for
livestock grazing is altered appreciably, this change would affect ranching profits and possibly
overall business viability. Ranching is the significant portion of the income for all five permittees for
this landscape.
The regional economy surrounding sheep grazing includes more than just livestock production. The
related economics of winter pasture rental and agricultural products currently also play a role in the
regional agricultural economy as a whole.
ENVIRONMENTAL CONSEQUENCES
Alternative 1 –No Action
The No Action Alternative would reduce public land available for livestock grazing by roughly
172,000 acres. This acreage includes Forest Service and BLM acreage from all the allotments in the
landscape except the one allotment (Silverton Watershed) that is already closed to grazing. From a
regional perspective, this loss of public livestock grazing acreage would not be noteworthy.
However, locally this acreage is important because it contributes greatly to the viability of five
private land ranches. The private ranch lands are not economic units in themselves, and rely on the
public lands for viability of their operations. High land prices prohibit the addition of more private
lands for ranching. Besides the obvious value to the ranching families, the viability of the ranches is
valuable to the community at large for open space, wildlife habitat, and other amenities.
Preservation of the ranching sector is essential to the economic health of the region (PSU 2001).
Alternative 1 would have the greatest negative social impact to local communities as the elimination
of all livestock grazing on all allotments would cause dependent ranching operations to go out of
business. If individuals and families move from the area, communities may lose their leaders,
volunteers, participants, or other types of community energy and capacity in terms of residents. In
addition to loss of human resources, selling of ranches often results in the splitting and subdivision
of value-rich lands.
Alternative 2
Continuation of the current situation would not create any further costs to operations grazing on
FS/BLM lands. Outside forces, such as interest rates, fuel prices, or market conditions could change
the margin of profit for any operation regardless of AUM’s grazed on federal lands, but there would
likely be no change from the current economic situation due to FS/BLM action.
Alternative 3
Alternative 3 requires allotments be managed more actively than Alternative 2 due to new design
criteria. Because of the flexible nature of adaptive management, it is difficult to predict the impact
to ranching operations. Some operators may be effective in monitoring and adjusting to adaptive
97

management options, while others may be unable to adapt to the new conditions. As with
Alternative 2, outside forces play a large role in the ability for ranchers to maintain an operation’s
profitability.
Some ranches may not be able to adapt to the new management practices and/or profit margins could
become too small to remain in business. Some ranching operations could possibly fail.
Socially, Alternative 3 would have greater benefit and value to a larger number of interest groups
than Alternative 2. People who are interested in protecting and improving resources including
wildlife and fish habitat, protecting a primitive wilderness experience, and increasing hunting and
fishing opportunities would see their values reflected more in the management activities associated
with Alternative 3.
Alternative 3 also has a social benefits to the permittees and the grazing industry. The inclusion of
new design criteria, which are intended to minimize and resolve issues with other resources, may
result in a better social acceptance of sheep grazing, lessening pressure to eliminate it altogether.
Environmental Justice: Executive Order 12898 requires that all federal actions consider the
potential of disproportionate effects on minority and low-income populations in the local area of the
proposed action. While the individual permittees may be part of a population of concern under the
Order, the population of Montrose County is neither greater than 50% minority nor greater than 50%
low-income (US Census Bureau, 2000); and therefore, there will be no disproportionate impacts on
subject populations.
CUMULATIVE IMPACTS
Factors other than ranching have, and will continue to make an impact on the socioeconomic climate
of Montrose county. An influx of retirees has increased the draw on government programs and the
need for certain services. Tourist demand for lodging and restaurant services is now becoming a
major sector. Retail has become the area’s major employer, but this sector generates low annual
wage-related income. Agriculture’s vitality is threatened by increasing urbanization and tourism,
which inflates land values and tends to result in conversion of land to residential and recreational
uses (PSU 2001).
98

Cultural Resources _______________________________
AFFECTED ENVIRONMENT
There is evidence of occupation of the analysis area from approximately 10,500 years ago to the
present. During prehistoric times, the analysis area was primarily utilized on a seasonal basis for
resource procurement activities such as hunting and plant gathering. This occupation is affiliated
with paleoindian, archaic, and protohistoric (Ute) cultures. Evidence of historic occupation includes
the remains logging, mining, ranching, and herding activities. The historic period occupation in the
analysis area is affiliated with European-American, Hispanic-American, and Native-American
cultures.
The analysis area for this grazing assessment is the 195,050 acres of land within the Silverton
Landscape. A review of existing San Juan National Forest, Bureau of Land Management, and
Colorado Historical Society records was conducted to identify previous incidences of archaeological
survey and known historic properties within the analysis area. Sixty seven cultural resource
inventories have been completed in the analysis area within the past 30 years, resulting in
approximately 3,560 acres of intensive level inventories. Reconnaissance surveys have also occurred
in the analysis area, but the existing records do not typically specify the amount of acreage examined
during this type of inventory. Most of the previous surveys were conducted in advance of abandoned
mine reclamation, mine safety closures, livestock grazing, proactive cultural resource surveys, ski
area development, minor land use authorizations, and timber management.
The Colorado Historical Society’s records indicate that 444 cultural resources have been identified
within the analysis area. The majority of sites in the general region of the analysis area consist of
historic features associated with precious metal and mineral exploration and extraction. A smaller
percentage are attributed to transportation, open range grazing and timber production. The northern
portion of the analysis area experienced several hard rock mining boom and bust cycles, resulting in
a high density of historic mining sites. The southern half of the analysis area experience a limited
amount of mineral exploration and development, and consequently possesses a much lower site
density. Records indicate a historic Ute presence in portions of the APE. Few prehistoric sites are
known to be present in the analysis area. They are typically the remains of small open prehistoric
camps evidenced by lithic artifacts or isolated incidences of lithic tool maintenance or manufacture.
Area of Potential Effects
Under 36 CFR 800.16(d) the Area of Potential Effects (APE) is the geographic area or areas within
which an undertaking may directly or indirectly cause alterations in the character or use of historic
properties, if any such properties exist. The Area of Potential Effects is influenced by the scale and
nature of the undertaking and may be different for different kinds of effects caused by the
undertaking. Under Alternatives 2 and 3, the potential to affect historic properties would be limited
to the allotments which are proposed to remain active, or are proposed for emergency use. As
Colorado is a fence-out state, and very little fencing of private property is present in the analysis
area, grazing does occur on private property within the active allotments. As grazing on private
property is considered a connected action, non-federal lands are included in the APE.
Under Alternative 2, the APE would be those allotments that would remain active (82,890 acres).
Forty three cultural resource inventories have been completed in the APE for Alternative 2 within
the past 30 years, resulting in approximately 1,782 acres of intensive level inventories. Within the
Alternative 2 APE, 410 cultural resources have been identified. Of this number, 236 are considered
not eligible for the National Register of Historic Places (NRHP). Forty sites require additional data
99

prior to evaluating them for the NRHP and are currently considered potentially eligible. The
remaining 134 sites are eligible for the NRHP.
Under Alternative 3, the APE would be those allotments proposed as active and as forage reserve
(99,058 acres). Fifty nine cultural resource inventories have been completed in the APE for
Alternative 3 within the past 30 years, resulting in approximately 2,221 acres of intensive level
inventories. Within the Alternative 3 APE, 422 cultural resources have been identified. Of this
number, 236 are considered not eligible for the National Register of Historic Places (NRHP). Forty
three sites require additional data prior to evaluating them for the NRHP and are currently
considered potentially eligible. The remaining 143 sites are eligible for the NRHP.
Compliance with Section 106 of the National Historic Preservation Act
BLM Colorado Instructional Memorandum No. CO-2002-29 and Washington Office WO-IM-99-
039 outline the guidelines and procedures for evaluating the effect of issuing, renewing, and
transferring grazing permits on historic properties.
The San Juan National Forest drafted a document titled Standard Range Rescission Strategy for
Cultural Resources to provide specific direction and guidance for accomplishing the Section 106
process for open range grazing permit renewal. Consultation with the Colorado State Historic
Preservation Officer on this guidance was completed on June 25, 2008 (CHS #51571).
Per the BLM instructional memorandum, the analysis on BLM lands focused on areas where
livestock concentrations may have an adverse effect on historic properties (National Register eligible
or listed sites). Per the San Juan National Forest Standard Range Rescission Strategy for Cultural
Resources, the focus of the analysis is known livestock congregation areas and their intersection
with areas known or likely to contain cultural resources. Such locations within allotments that are
currently active and proposed to remain open to sheep grazing were examined during field analysis
efforts conducted for this undertaking.
The Forest/BLM rangeland management staff defined areas where livestock are known to
congregate within the APE. Predictive variables for sheep concentration included known bedding
areas, salting locations, water sources, and landscape choke points that contributed to severe trailing.
Known herder camp locations were also considered. A computer mapping site prediction model was
run to identify areas likely to contain cultural resources. The model utilized environmental factors
such as proximity to water, slope, and vegetation types. Site records, orthophotos and the San Juan
Public Lands suitable sheep grazing acres GIS layer were used to further refine new survey areas.
Additional intensive sample survey was also planned in suitable sheep forage areas on slopes of less
than 30% to assess the accuracy of the inventory strategy.
Three locations on National Forest lands within the Area of Potential Effects for Alternatives 2 and 3
were identified by the Rangeland Management Staff and the Archaeologist as meeting the definition
of intersection areas between sheep concentration and areas known or likely to contain cultural
resources. Seven locations on BLM were identified as areas where sheep concentration could be
causing impacts to historic properties. Seventeen herder camps were identified within areas of higher
site potential. The records search indicated that most of these locations lacked previous survey and
that there are no known cultural resources in these locations.
Approximately 158 acres of new survey was conducted for this analysis. Ninety one acres of new
intensive survey was conducted in sheep concentration areas and herder camps that lacked previous
survey and were likely to contain cultural resources. An additional sixty seven acres of intensive
sample survey was conducted in sheep grazing areas outside of identified sheep congregation
locations.
100

A cultural resource report containing survey results, National Register determinations, and grazing
effects on historic properties was produced and sent to the Colorado State Historic Preservation
Officer.
ENVIRONMENTAL CONSEQUENCES
The Heritage Resources objective of the Rangeland Allotment Management Planning on the
Silverton landscape is to protect historic properties from impacts related to the continued permitting
of livestock grazing. Concentrated livestock grazing has the potential to directly affect historic
properties through trampling or displacement. Overgrazing can result in a decrease in vegetation and
an increase in the amount of bare soil within a site. Typical dispersed sheep grazing patterns are
unlikely to impact cultural resources. Sheep congregation and overgrazing would typically occur at
sheep bedgrounds. Concentrated trailing generally occurs at choke points formed by landscape
features that restrict sheep movement options. Repeated livestock trailing in the same areas can form
new intermittent drainages within a site. Poor sheep bedground management, repeated use of the
same salting locations, and continued use the same trailing routes for moving sheep bands have the
potential to impact cultural resources. Both overgrazing and livestock trailing have the potential to
indirectly affect historic properties by causing or enhancing erosion within archaeological sites.
Sheep herder campsites, when located on an archaeological site, can disturb site deposition and
surface artifacts. Sheep herders could use wooden components of historic cultural resources for
firewood.
The effects of a proposed project are taken into consideration for cultural resources that are eligible
or potentially eligible for the National Register of Historic Places. Cultural resources determined to
be ineligible for inclusion in the Register do not require protection, and don’t warrant further
consideration of effects from the proposed project. The recording of this class of cultural resources
has exhausted their data potential, and effectively mitigated any impacts that may occur to them.
Alternative 1 –No Action
Since livestock grazing would not occur under this alternative, there would be no direct impacts
from sheep grazing activities to historic properties in the analysis area. There is some potential for
indirect impacts associated with current grazing practices to occur short term, but these would likely
cease as well. The elimination of livestock grazing should result in an increase in the abundance,
distribution and vigor of plant species which would increase the amount of ground cover (vegetation
and litter) and soil organic matter, and decrease the amount of bare soil, which would decrease the
potential for soil erosion, compaction, and runoff. This would have a generalized beneficial effect on
archaeological sites. Potential impact areas as sheep bedding grounds, concentrated sheep trailing
locations, and associated herder camps would be eliminated. An indirect impact from the elimination
of livestock grazing is that future surveys that might be required for the authorization of structural
range improvements would not be conducted, and the opportunity for that survey would be lost.
Alternative 2
The potential for current livestock grazing practices to have direct or indirect impacts to eligible sites
and potentially eligible sites located within the APE would remain the same or possibly lessen if the
trend of a significant decrease in the historic numbers of sheep grazed continues. Current grazing
practices would continue to maintain problems areas on the landscape caused by poor bed ground
management, repeated use of the same salting locations, and repeated sheep trailing through the
same areas. Problem areas on the landscape caused by the historic grazing practices would be
unlikely to improve. Allowing livestock grazing to continue under current range management would
maintain the established trends in rangeland conditions. Existing abundance, distribution and vigor
of plant species due to livestock grazing, along with their influence on soils, would continue in its
101

present state. In general, where undesirable impacts are occurring to eligible or potentially eligible
archaeological sites due to soil movement by rills and gullies, sheet erosion and scouring, they
would likely continue. Eligible or potentially eligible archaeological sites located in areas not
meeting or moving toward the desired conditions could experience downward trends in vegetative
cover and soil stability, since no new improvements or livestock grazing system changes would be
implemented to positively affect those conditions. Eligible or potentially eligible archaeological sites
located in areas already meeting or moving towards desired conditions would likely remain in a
stable condition, barring any factors that contribute to livestock concentration.
The Animas Forks townsite is a National Register eligible site located along sheep herding routes
associated with the grazing of the Eureka/California Gulch and Picayne /Mineral allotments. The site
could be disturbed if the sheep were repeatedly driven through it. Per the site specific design criteria,
the sheep will be trailed around the townsite by moving the sheep on the ridges above the site or
along the county road on the east side of the Animas River. The implementation of this design
criteria should protect the site from impacts associated with sheep trailing.
There are no additional known eligible or potentially eligible sites within identified sheep
congregation areas or herder camps. No impacts to eligible or potentially sites from sheep grazing
activities were observed.
Future maintenance of existing rangeland management improvements and grazing management
activities (such as herder camp locations, heavily utilized bedding grounds and salting locations,
repeated sheep trailing, and corral reconstruction) should consider potential impacts to historic
properties prior to implementation.
Alternative 3
Under Alternative 3, the potential for direct and indirect impacts to eligible and potentially eligible
sites located within the APE should lessen, as opposed to Alternative 2. In general, an increase in the
abundance, distribution and vigor of the forage species would be likely to occur, which would
increase the amount of ground cover (vegetation and litter) and soil organic matter, and decrease the
amount of bare soil, which would increase infiltration and decrease runoff and erosion. Those areas
that currently do not meet desired conditions would have the best chance to improve conditions
because of the more responsive and flexible type of livestock grazing management under this
alternative. This would be a benefit for eligible or potentially eligible archaeological sites located in
areas not meeting desired conditions, as they would likely trend towards a more stable condition,
barring any factors that contribute to livestock concentration. The design criteria specific to this
alternative (those in particular that address livestock bedding, trailing, salting, and herder camps)
should result in a decrease of potential impacts to historic properties. As Alternative 3 would result
in the closure of four allotments, there should be a benefit for cultural resources in these allotments
identical to that discussed under Alternative 1.
The Animas Forks townsite is a National Register eligible site located along sheep herding routes
associated with the grazing of the Eureka/California Gulch and Picayne /Mineral allotments. The site
could be disturbed if the sheep were repeatedly driven through it. Per the site specific design criteria,
the sheep will be trailed around the townsite by moving the sheep on the ridges above the site or
along the road on the east side of the basin. The implementation of this design criteria should protect
the site from impacts associated with sheep grazing.
There are no additional known eligible or potentially eligible sites within identified sheep
congregation areas or herder camps. No impacts to eligible or potentially eligible sites from sheep
grazing activities were observed.
102

As the Graysill Allotment has not been grazed since 1966, it is likely that rangeland health
conditions very good. The Flume Allotment was last grazed on a regular basis in 1983. During the
Missionary Ridge Fire, a band permitted on the Missionary Ridge S&G allotment grazed in this
allotment. It is probable that rangeland health conditions have improved greatly in the Flume.
Former problem areas due to historic livestock congregation areas or overstocking are unlikely to be
readily apparent in these allotments. Emergency use of these allotments is likely to be infrequent,
suggesting that rangeland health conditions will follow a general trend of future improvement.
All eligible and potentially eligible sites should be avoided by future rangeland management
improvements and grazing management practices such as herder camp locations, heavily utilized
bedding grounds and salting locations, repeated sheep trailing, and corral reconstruction.
CUMULATIVE IMPACTS
Activities and actions other than livestock grazing that have or will be occurring in the analysis area
could impact cultural resources. These include recreational use, fire suppression activities, fuels
reduction (mechanical and prescribed burning), and timber harvest activities. Typically, planned
actions of the Forest Service such as timber harvest, trail constriction, and fuels reduction require a
cultural resource clearance which would require avoidance of negative impacts to cultural resources.
However, unforeseen or unregulated activities have greater potential for impacting cultural
resources. For example, wildfire could burn standing structures, or fire suppression activities could
disturb artifacts during fireline construction. Personal firewood gathering has the potential to remove
aspen art. Illegal artifact collection occurs and can be exacerbated by increased public access.
Natural or man-caused erosion could expose or wash artifacts away.
The northern portion of the analysis area contains a higher site density, and a concentration of
thematic sites, and could be considered a cultural landscape. However, cumulative impacts to
cultural resources in the northern portion of the analysis area would typically be isolated incidences,
rather than landscape level impacts.
103

CHAPTER 4 - CONSULTATION AND COORDINATION
The FS/BLM informed the following Federal, state, and local agencies, and tribes during the
development of this environmental assessment:
FS/BLM TEAM MEMBERS:
Team Leader/Recreation: Cam Hooley Hydrologist: Kay Zillich
NEPA Coordinator: Cam Hooley
Archeologist: Bruce Bourcy
Range Specialist: Rowdy Wood
Ecologist: Jeff Redders
Wildlife Biologist: Chris Schultz
Recreation/Wilderness: Nancy Berry
FEDERAL, STATE, AND LOCAL AGENCIES:
Colorado Division of Wildlife
Ouray County
Colorado State Historic Preservation
San Juan County
Officer
Town of Silverton
Colorado State Land Board
La Plata County
USDI Fish and Wildlife Service
TRIBES:
Hopi Tribe
Jicarilla Apache Nation
Navajo Nation
Northern Ute Tribe
Ohkay Owinge
Pueblo of Acoma
Pueblo de Cochiti
Pueblo of Isleta
Pueblo of Jemez
Pueblo of Laguna
Pueblo of Nambe
Pueblo of Picuris
Pueblo of Pojoaque
Pueblo of Sandia
Pueblo of San Felipe
Pueblo of San Ildefonso
Pueblo of Santa Ana
Pueblo of Santa Clara
Pueblo of Santo Domingo
Pueblo of Taos
Pueblo of Tesuque
Pueblo of Zia
Southern Ute Indian
Tribe
Ute Mountain Ute Tribe
Zuni Pueblo
104

APPENDIX A - ACRONYMS AND GLOSSARY
AMP – Allotment Management Plan
APE – Area of Potential Effect (for cultural resources)
AOI – Annual Operating Instructions
AUM – Animal Unit Month
BA – Biological Assessment (for Threatened and Endangered Species)
BE – Biological Evaluation (for Sensitive Species)
BLM- Bureau of Land Management
CDOW – Colorado Division of Wildlife
CF – Cover Frequency (vegetation evaluation method)
CFR – Code of Federal Regulations
DEIS – Draft Environmental Impact Statement
EA – Environmental Assessment
EIS – Environmental Impact Statement
FS – Forest Service
FSH – Forest Service Handbook
FSM – Forest Service Manual
GRI – Grazing Response Index
LAU – Lynx Analysis Unit
LCAS – Lynx Conservation Assessment and Strategy
LHA – Standards for Public Land Health Assessment
MIS – Management Indicator Species
NEPA – National Environmental Policy Act
NRHP – National Register of Historic Places (for cultural)
OHV – Off Highway Vehicle (ATVs, motorcycles, and other unlicensed motor vehicles)
PNV – Present Net Value
PFC – Proper Functioning Condition (for riparian areas)
RHM – Rangeland Health Matrix Evaluation
RMP- Resource Management Plan (for BLM lands)
SJNF – San Juan National Forest
USFS – United States Forest Service
WIZ – Water Influence Zone
105

APPENDIX B - CITATIONS AND REFERENCES
40 CFR 1500. 1986. CEQ Regulations for the National Environmental Policy Act.
Arnold, G.W. and M.L. Dudzinski. 1978. Ethology of free-ranging domestic animals. Elsevier, NY
Aune, K., N. Anderson, D. Worley, L. Stackhouse, J. Henderson, J. Daniel. 1998. A comparison of
population and health histories among seven Montana bighorn sheep populations. Proc. Bienn.
Symp. North. Wild Sheep and Goat Counc. 11:46-69.
Baker, William L. 1983. Alpine Vegetation of Wheeler Peak, New Mexico, USA: Gradient Analysis,
Classification, and Biogeography. Arctic and Alpine Research, Vol. 15, No. 2, pp. 223-240, 1983.
Banci, V. 1994. Wolverine. Pages 99-127 in the scientific basis for conserving carnivores, American
marten, fisher, lynx, and wolverine in the western United States. L. F. Ruggiero, K. B. Aubry, S.
W. Buskirk, L. J. Lyon, and W. J. Zielinski, tech. eds. USDA For. Serv. Gen. Tech. Rep. RM-254.
Fort Collins, CO.
Beecham, J. J., C. P. Collins, and T. D. Reynolds. 2007. Rocky Mountain bighorn sheep (ovis
canadensis): a technical conservation assessment. [Online]. USDA Forest Service, Rocky
Mountain Region. Available on the world wide web at:
http://www.fs.fed.us/r2/projects/scp/assessments/rockymountainbighornsheep.pdf.
Bove, D.J., Yager, D.B., Mast, M.A., and Dalton, J.B. 2007. Alteration map showing major faults
and veins and associated water-quality signatures of the Animas River watershed headwaters
near Silverton, southwest Colorado: U.S. Geological Survey Scientific Investigations Map 2976,
18-p. pamphlet, 1 plate, scale 1:24,000.
Braun, C. E., R. W. Hoffman, and G. E. Rogers. 1976. Wintering areas and winter ecology of whitetailed
ptarmigan in Colorado. Colorado Division of Wildlife Spec. Rep. No. 38. W-R-S-38-’76.
Denver, CO. 35 pp.
Briske, D.D. and Richards, J. 1995. Plant Responses to Defoliation. In Wildland Plants.
Physiological Ecology and Developmental Morphology, Edited by Donald Bedunah and Ronald
Sosebee.
Caldwell, M.M., J.H.Richards, D.A.Johnson, R.S.Nowak, R.S.Dzurec. 1981. Coping with herbivory:
Photosynthetic capacity and resource allocation in two semiarid Agropyron bunchgrasses.
Oecologia 50:14-24.
Colorado Division of Wildlife. 2006. Colorado’s comprehensive wildlife conservation strategy and
wildlife action plans. Available on the world wide web at:
http://wildlife.state.co.us/WildlifeSpecies/ColoradoWildlifeActionPlan/. Accessed 06/17/2009.
Colorado Division of Wildlife. 2007. Colorado Listing of Endangered, Threatened and Wildlife
Species of Special Concern. Available on the world wide web at:
http://wildlife.state.co.us/species_cons/list.asp. Accessed 3/7/2007.
Cook, Clyde J., C. Wayne Cook, and Lorin E. Harris. 1948. Utilization of Northern Utah Summer
Range Plants by Sheep. J. For. 46(6): 416-425.
Dadkhah, M. and G.F. Gifford. 1981. Influence of vegetation, rock cover and trampling on
infiltration rates and sediment production. Water Resources Bulletin 16: 979-985.
Diamond, B. 2005. Abbreviated summary for Unit S-33, the Pole Mountain/Upper Lake Fork
106

ighorn sheep herd. Unpublished report, Colorado Division of Wildlife, Fort Collins, CO. 6 pp.
Dick-Peddie, William A. 1993. New Mexico vegetation, past, present, and future. University of NM
Press.
DuBois, C. 1903. Report on the proposed San Juan Forest Reserve, Colorado. Unpublished Report
on file at the supervisor’s office of the San Juan National Forest.
Dunford, E.G. 1954. Surface runoff and erosion from pine grasslands of the CO Front Range. Journal
of Forestry 52:923-927.
EPA. 1987. Nonpoint Source Controls and Water Quality Standards. Environmental Protection
Agency. Memo #NPS: FY-87-49, August 19, 1987.
EPS. 2009. A SocioEconomic Profile of Montrose County, Colorado. Produced by the Economic
Profile System, www.headwaterseconomics.org
Executive Order 12898. 1994. Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations.
Forsling, C.L. 1931. A study of the influence of herbaceous plant cover on surface runoff and soil
erosion in relation to grazing on the Wasatch Plateau in Utah. Tech Bulletin 220, USDA.
FSH 2200. 2005. Range Management Handbook. USDA Forest Service.
FSH 2209.13. 2007. Grazing Permit Administration Handbook. USDA Forest Service, R2 Interim
Directive # 2209.13-2007-8.
FSH 2509.25. 2006. Watershed Conservation Practices Handbook. USDA Forest Service, Rocky
Mountain Region.
Gary, Howard L. and Joch C. Adams. 1985. Indicator bacteria in water and stream sediments near
the Snowy Range in southern Wyoming in Water, Air, and Soil Pollution 25 (1985) 133-144.
0049-6979/85.15.D. Reidel Publishing Company.
George, J. L., R. Kahn, M. W. Miller, and B. Watkins. 2008. Colorado bighorn sheep management
plan 2008 – 2018. Colorado Division of Wildlife, 6060 Broadway, Denver, CO, 80216. 96 pp.
Heitschmidt and Stuth. 1993. Grazing Management - An Ecological Perspective, Timber Press Inc.
Hoffman, R. W. 2006. White-tailed ptarmigan (Lagopus leucura): a technical conservation
assessment. USDA Forest Service, Rocky Mountain Region. Available on line at:
http://www.fs.fed.us/r2/projects/scp/assessments/whitetailedptarmigan.pdf. Accessed
02/19/2009.
Holechek, J.L,Gomes, H.,Molinar, F.Galt, D. 1998; Grazing Intensity: Critique and
Approach.Rangelands 20(5).
Holechek, J.L. 1981. Livestock Grazing Implications on Public Lands; A Viewpoint. JRM 34;251-
254.
Johnson. 1962.
Larison, J. R., G. E. Likens, J. W. Fitzpatrick, and J. G. Crock. 2000. Cadmium toxicity among
wildlife in the Colorado Rocky Mountains. Nature 406:181-183.
Larison, J. R., G. E. Likens, J. W. Fitzpatrick, and J. G. Crock. 2000. Cadmium toxicity among
wildlife in the Colorado Rocky Mountains. Nature 406:181-183.
Lull, H.W. 1959. Soil compaction on forest and range lands. Miscellaneous publication 769, USDA.
107

Martin, K.D., T.J. Schommer, and V.L. Coggins. 1996. Literature review regarding the compatibility
between bighorn and domestic sheep. Proc. Bienn. Symp. North. Wild Sheep and Goat Counc.
10:72-77.
McNaughton, S.J. 1983. Compensatory plant growth as a response to herbivory. Oikos 40:329-336
Nelson, D. L. 1998. Brown-capped rosy-finch. Pages 522-523 in Colorado breeding bird atlas, H. E.
Kingery, ed. Colorado Bird Atlas Partnership and Colorado Div of Wildlife, Denver, CO.
Onderka, D.K. and W.D. Wishart. 1984. A major bighorn sheep die-off from pneumonia in southern
Alberta. Proc. Bienn. Symp. North. Wild Sheep and Goat Counc. 4:356-363.
Orr, H.K. 1975. Recovery from soil compaction on bluegrass range in the Black Hills.
P.L. 104-19. 1995. Rescissions Act.
P.L. 86-517. 1960. Multiple Use Sustained Yield Act.
P.L. 91-190. 1970. The National Environmental Policy Act of 1969, as Amended.
P.L. 94-579. 1976. Federal Land Policy and Management Act.
Pannell. 2006. Soil Survey of Animas-Dolores Area, Colorado, Parts of Archuleta, Dolores,
Hinsdale, La Plata, Montezuma, San Juan, and San Miguel Counties. [CD-ROM]. United States
Department of Agriculture, Natural Resources Conservation Service.
Paulsen, Harold A. Jr. 1960. Plant Cover and Forage Use of Alpine Sheep Ranges in the Central
Rocky Mountains.
Penn. State Univ. 2001. Economic Base Assessment of Delta and Montrose Counties, Colorado.
Monitoring and Assessment Team, Institute for Policy Research and Evaluation, Pennsylvania
State Univ.
Prichard, Don. 1998. A User Guide to Assessing Proper Functioning Condition and Supporting
Science for Lotic Areas, BLM Technical Reference 1737-15.
Quimby, Chuck. 2006. Draft. A Practical Approach to Adaptive Management. USDA Forest Service
Rocky Mountain Region. Unpublished.
Raby, Kim S. 2005. Use of Water Quality Data for Land Management Decisions: A Case Study in
San Juan County, Colorado. University of Colorado.
Redders, Jeffery S. 2003. Riparian Area and Wetlands Classification for the San Juan National
Forest. Unpublished.
Redders, Jeffery. 2009 Silverton Range Landscape Biological Evaluation for Plants.
Romme, W.H., M.L. Floyd, D. and Hanna, H.D. Final Report. 2006. Landscape Condition Analysis
for the South Central Highlands Section, Southwestern Colorado and Northwestern New
Mexico.
Ruggiero, L. F., K. B. Aubry, S. W. Buskirk, G. M. Koehler, C. J. Krebs, K. S. McKelvey, and J. R.
Squires. 2000. The scientific basis for lynx conservation: qualified insights. Pages 443-454 in
Ruggiero, L.F., K. B. Aubry, S. W. Buskirk, G. M. Koehler, C. J. Krebs, K. S. McKelvey, and J.
R. Squires. (Tech. Eds.). Ecology and conservation of lynx in the United States. Univ. Press of
Colorado. Boulder, CO. 480 pp.
San Juan National Forest. 1992. Land and Resources Management Plan, as Amended. USDA Forest
Service Rocky Mountain Region.
108

San Juan National Forest. 1998. Wilderness Management Direction Amending the Land and
Resource Management Plan. USDA Forest Service Rocky Mountain Region.
San Juan National Forest. 2005. Columbine RD Rescission Schedule Revision. Unpublished.
San Juan National Forest. 2009. Domestic Sheep Numbers Over Time. Unpublished spreadsheet.
Schultz, Chris. 2009a. Biological Assessment for Federally Listed Species for Silverton Grazing
Analysis Landscape.
Schultz, Chris. 2009b. Biological Evaluation for U.S. Forest Service and BLM Designated Sensitive
Species for Silverton Grazing Analysis Landscape.
Schultz, Chris. 2009c. Wildlife Review for San Juan National Forest Fish and Wildlife Management
Indicator Species.
Simon, W., Butler, P. , Owen, R. 2001. Use Attainability Analysis for the Animas River Watershed.
Animas River Stakeholders Group (presented to Colorado Water Quality Control Commission
for the adoption of steam standards).
Smith, D.W. 1967. Effects of cattle grazing on a ponderosa pine-bunchgrass range in CO.
Thilenius, John F. 1975. Alpine Range Management In the Western United States – Principles,
Practices, and Problems: The Status of Our Knowledge. USDA Forest Service Research Paper
RM-157.
Towry, R.K. 1984. Wildlife habitat requirements. Pages 174-177 in Hoover, R.L., and D.L. Wills
eds. Managing forested stands for wildlife. Colorado Division of Wildlife in cooperation with
USDA Forest Service, Rocky Mountain Region Denver, CO.
US Census Bureau. 2000. Profile of General Demographic and Select Economic Characteristics:
2000, Montrose County, Colorado.
USDA. 2006. Bacteria Analysis Strategy for Rangeland Management Projects. USDA Forest Service
Rocky Mountain Region. Feb. 16, 2006.Unpublished.
USDI, BLM. 1985. San Juan/ San Miguel Planning Area Resource Management Plan. Montrose
District, Colorado/
USDI, BLM. 1997. Colorado Public Land Health Standards and Guidelines for Livestock Grazing.
March 1997.
USDI, BLM. 2004. Silverton Outdoor Learning and Recreation Center, FEIS. San Juan Public Lands
Center, Durango, Colorado.
USDI, Fish and Wildlife Service. 2002. Birds of conservation concern 2002. Division of Migratory
Bird Management, Arlington, Virginia. 99 pp. Available on the world wide web at:
http://migratorybirds.fws.gov/reports/bcc2002.pdf.
Vallentine, John F. 1990. Grazing Management. Page 240. Academic Press Inc. San Diego, CA.
Versaw, A.E. 1998. American pipit. Pages 410-411 in Colorado breeding bird atlas, H. E. Kingery,
ed. Colorado Bird Atlas Partnership and Colorado Div of Wildlife, Denver, CO.
Virden, Randy J., Richard C. Knopf, Christine A. Vogt, and Kevin W. Larkin. 1999. Final Report of
the Alpine Loop Backcountry Byway Customer Study. Department of Recreation Management
and Tourism, Arizona State University.
Wait, S. 2007. Personal Communication. Notes from phone conversation with Scott Wait on
February 14, 2007. Regional Terrestrial Biologist, Colorado Division of Wildlife, Southwest
109

Regional Office, Durango, CO.
Western Association of Fish and Wildlife Agencies (WAFWA). 2007. Wild Sheep Working Group.
Recommendations for domestic sheep and goat management in wild sheep habitat, June 21,
2007.
110

APPENDIX C - WILDLIFE SPECIES LISTS
Species
Federal
Status
Table C-1. Federally Listed Species
for the San Juan Public Lands.
Habitat Present In the
Landscape?
Canada lynx Threatened Yes - mature spruce fir,
cool-moist mixedconifer,
and willow -
riparian areas; 3
designated linkage
areas intersect the
Landscape
Mexican
spotted owl
Southwestern
willow
flycatcher
Threatened No – no narrow rockwalled
canyons with
mixed-conifer
Endangered Yes – 2 patches of
apparently suitable
habitat occur in the
Landscape
Bonytail Endangered No - does not occur in
or downstream of
Animas River Basin
Colorado
pikeminnow
Endangered No – does not occur in
Animas River Basin
Humpback chub Endangered No - does not occur in
or downstream of
Animas River Basin
Razorback
sucker
Uncompahgre
fritillary
butterfly
Endangered No – does not occur in
Animas River Basin
Endangered Yes – 1 patch of habitat
thought suitable, but
protocol surveys not
conducted
Species
Habitat Present In the
Silverton Landscape?
Birds (23)
American bittern (FS) No – no marsh, swamp, or bog
with cattails, rushes, grasses, &
sedges, not known to occur in
San Juan County
American peregrine
falcon (BLM and FS)
Probability of
Occurrence in
the Landscape
High - animals
documented to
occur in the
Landscape.
Carried
Forward for
Further
Analysis?
Yes, see
discussion
Low No, dismissed
from further
Low – birds not
documented to
occur during
breeding season
in or near the
Landscape, but
suitable habitat is
present
Low – no water
depletions from
the San Juan
River basin
Low – no water
depletions from
the San Juan
River basin
Low – no water
depletions from
the San Juan
River basin
Low – no water
depletions from
the San Juan
River basin
High - 1 patch of
habitat thought
suitable, but
protocol surveys
not conducted
evaluation.
Yes, see
discussion.
No, dismissed
from further
evaluation.
No, dismissed
from further
evaluation.
No, dismissed
from further
evaluation.
No, dismissed
from further
evaluation.
Yes, see
discussion
Table C-2. FS Region 2 and Colorado BLM Sensitive Species.
Yes – suitable foraging habitat,
but not known to nest in San
Juan County.
Species or Habitat
Impacted by Action
Alternatives?
Project Effects
Determination
May Effect, Not
Likely to Adversely
Affect
No Effect
May Effect, Not
Likely to Adversely
Affect
No Effect
No Effect
No Effect
No Effect
May Effect, Not
Likely to Adversely
Affect
Project Impact
Determination
No Selecting Alternative 2 or 3
will have “no impact” on
American bittern. No further
discussion is required.
No –foraging habitat not
significantly affected by
sheep grazing
Selecting Alternative 2 or 3
will have “no impact” on
American peregrine falcon.
No further analysis is
required.
111

Species
Habitat Present In the
Species or Habitat
Impacted by Action
Project Impact
Silverton Landscape?
Alternatives?
Determination
American three-toed Yes – species occurs in
No – nesting and foraging Selecting Alternative 2 or 3
woodpecker (FS)
Landscape year round. About habitat (standing dead will have “no impact” on
60,696 acres of habitat in
trees) not significantly American three-toed
Landscape.
affected by sheep grazing woodpecker. No further
analysis is required.
Bald eagle (BLM and FS) No – no nesting or foraging No Selecting Alternative 2 or 3
habitat in Landscape, not known
will have “no impact” on
to nest and rarely observed in
bald eagle. No further
San Juan County
discussion is required.
Black swift (FS) Yes – known to nest and forage in No – nesting (waterfalls) Selecting Alternative 2 or 3
Landscape
and foraging habitat (in air will have “no impact” on
above alpine peaks) not black swift. No further
affected by sheep grazing analysis is required.
Black tern (BLM) No – no bulrush or cattail
No Selecting Alternative 2 or 3
marshes in Landscape, not
will have “no impact” on
known to occur in San Juan
black tern. No further
County
discussion is required
Boreal owl (FS) Yes – known to nest and occur No – nesting habitat Selecting Alternative 2 or 3
year round in the landscape and (standing dead trees) and will have “no impact” on
San Juan County. About 44,383 foraging habitat (closed boreal owl. No further
acres of habitat in Landscape. canopy spruce-fir forests)
not significantly affected
by sheep grazing
analysis is required.
Brewer’s sparrow (FS) No – no sagebrush in Landscape; No Selecting Alternative 2 or 3
not known to occur in San Juan
will have “no impact” on
County
Brewer’s sparrow. No further
discussion is required
Columbian sharp-tailed No – no habitat in Landscape; not No Selecting Alternative 2 or 3
grouse (FS)
known to occur in San Juan
will have “no impact” on
County
Columbian sharp-tailed
grouse. No further
discussion is required
Ferruginous hawk (BLM No – no suitable extensive
No Selecting Alternative 2 or 3
and FS)
grassland or prairie dog colonies
will have “no impact” on
in Landscape; not known to occur
ferruginous hawk. No further
in San Juan County
discussion is required
Flammulated owl (FS) Yes – known to nest and occur No – nesting habitat Selecting Alternative 2 or 3
year round in the landscape and (standing dead trees) and will have “no impact” on
San Juan County. About 7,965 foraging habitat (mixed- flammulated owl. No further
acres of habitat in Landscape. conifer and ponderosa
pine forests) not
significantly affected by
sheep grazing
analysis is required.
Gunnison sage grouse No – no sagebrush in Landscape; No Selecting Alternative 2 or 3
(BLM)
not known to occur in San Juan
will have “no impact” on
County
Gunnison sage grouse. No
further discussion is
required
Lewis’s Woodpecker (FS) No – no mature ponderosa pine No Selecting Alternative 2 or 3
or gambel oak in Landscape, not
will have “no impact” on
known to occur in San Juan
Lewis’s woodpecker. No
County
further discussion is
required
Loggerhead shrike (FS) No – no sagebrush or thorn shrub No Selecting Alternative 2 or 3
habitats in Landscape, not
will have “no impact” on
known to occur in San Juan
loggerhead shrike. No further
County
discussion is required
Northern goshawk (BLM Yes – foraging and nesting
No – nesting habitat not Selecting Alternative 2 or 3
and FS)
habitat in Landscape, known to affected, and, foraging will have “no impact” on
nest in San Juan County. About habitat not significantly northern goshawk. No
48,606 acres of habitat in
landscape.
affected by sheep grazing further analysis is required
Northern harrier (FS) No - no suitable wetlands or No Selecting Alternative 2 or 3
cattail marshes in Landscape, not
will have “no impact” on
known to nest in San Juan
northern harrier. No further
County
discussion is required
112

Species
Olive-sided flycatcher
(FS)
Habitat Present In the
Silverton Landscape?
Yes – suitable nesting habitat in
Landscape, known to nest in San
Juan County. About 21,344 acres
of habitat in Landscape
Purple martin (FS) No – no suitable mature aspen
stands in Landscape, not known
to nest in San Juan County
Short-eared owl (FS) No - no suitable wetlands or
cattail marshes in Landscape, not
known to nest in San Juan
County
Western Burrowing owl
(FS)
Western yellow-billed
cuckoo (BLM and FS)
No – no suitable extensive
grassland or prairie dog colonies
in Landscape not known to occur
in San Juan County
No – no suitable gallery
cottonwood forest in Landscape,
not known to occur in San Juan
County
White-faced ibis (BLM) No – no suitable wet meadows,
marsh edges or reservoir
shorelines in Landscape, not
known to occur in San Juan
County
White-tailed ptarmigan
(FS)
Fish (4)
Bluehead sucker (BLM
and FS)
Colorado River cutthroat
trout (BLM and FS)
Flannelmouth sucker
(BLM and FS)
Roundtail chub (BLM
and FS)
Yes- known to occur year round
in Landscape
No – no suitable streams or rivers
in Landscape
No – no conservation populations
in Landscape
No – no suitable streams or rivers
in Landscape
No – no suitable streams or rivers
in Landscape
Amphibians (2)
Boreal toad (FS) No – not known to occur in the
Landscape or in San Juan
County
Northern leopard frog
(FS)
Yes – possibly occurs at lowest
elevations of Landscape and
southern edge of San Juan
County. About 3,430 acres of
habitat in Landscape.
Species or Habitat
Impacted by Action
Project Impact
Alternatives?
Determination
No – nesting habitat (large, Selecting Alternative 2 or 3
live overstory conifer trees) will have “no impact” on
and foraging habitat olive-sided flycatcher. No
(aerial insects in tree further analysis is required
canopy) not significantly
affected by sheep grazing
No Selecting Alternative 2 or 3
will have “no impact” on
purple marten. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
short-eared owl. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
western burrowing owl. No
further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
western yellow-billed cuckoo.
No further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
white-faced ibis. No further
discussion is required
Yes – nesting and foraging
habitat (willows) shows
evidence of localized
impacts from sheep
grazing
No – no water depletions
from the Animas River
basin
No – sheep grazing is not
significantly altering
aquatic habitat structure,
and, no water depletions
from Animas River basin
No – no water depletions
from the Animas River
basin
No – no water depletions
from the Animas River
basin
No – sheep grazing is not
significantly altering
aquatic habitat structure
No - sheep grazing is not
significantly altering
aquatic habitat structure
Selecting Alternative 2 or 3
“may impact individual
white-tailed ptarmigan but
is not likely to result in a
loss of viability on the
planning area, nor cause a
trend to federal listing or a
loss of species viability
rangewide”.
Selecting Alternative 2 or 3
will have “no impact” on
bluehead sucker. No further
discussion is required
Selecting Alternative 2 or 3
will have “no impact” on
Colorado River cutthroat
trout. No further analysis is
required
Selecting Alternative 2 or 3
will have “no impact” on
flannelmouth sucker. No
further discussion is
required
Selecting Alternative 2 or 3
will have “no impact” on
roundtail chub. No further
discussion is required
Selecting Alternative 2 or 3
will have “no impact” on
boreal toad. No further
discussion is required
Selecting Alternative 2 or 3
will have “no impact” on
northern leopard frog. No
further analysis is required
113

Species
Mammals (13)
Allen’s big-eared bat
(BLM)
Habitat Present In the
Silverton Landscape?
No – Landscape too high in
elevation, not known to occur in
San Juan County
American marten (FS) Yes – known to occur year round
in Landscape. About 60,696
acres of habitat in Landscape.
Big free-tailed bat (BLM) No – Landscape too high in
elevation, not known to occur in
San Juan County
Desert bighorn sheep
(FS)
Fringed myotis (BLM and
FS)
Gunnison’s prairie dog
(FS)
New Mexico meadow
jumping mouse (BLM
and FS)
North American
wolverine (FS)
No – no desert canyons in
Landscape, not known to occur in
San Juan County
No – Landscape too high in
elevation, not known to occur in
San Juan County
No – no suitable extensive
grassland or prairie dog colonies
in Landscape not known to occur
in San Juan County
No – Landscape too high in
elevation, not known to occur in
San Juan County
Yes – denning and foraging
habitat present in Landscape, but
not confirmed to occur in San
Juan County in past 50 years
River otter (FS) Yes – known to occur in and near
the main stem Animas River.
About 103.6 miles of river habitat
in Landscape.
Rocky Mountain bighorn
sheep (FS)
Spotted bat (BLM and
FS)
Townsend’s big-eared bat
(BLM and FS)
Yes – known to occur in summer
in the Landscape. About 38,767
acres of mapped (CDOW) summer
range in Landscape.
No – too high elevation, not
known to occur in San Juan Co.
No – Landscape too high in
elevation, no open dry forests
Species or Habitat
Impacted by Action
Alternatives?
Project Impact
Determination
No Selecting Alternative 2 or 3
will have “no impact” on
Allen’s big-eared bat. No
further discussion is
required
No - foraging habitat
(closed canopy spruce-fir
forests) not significantly
affected by sheep grazing
Selecting Alternative 2 or 3
will have “no impact” on
American marten. No further
analysis is required
No Selecting Alternative 2 or 3
will have “no impact” on Big
free-tailed bat. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
desert bighorn sheep. No
further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
Fringed myotis. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
Gunnison’s prairie dog. No
further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
New Mexico meadow
jumping mouse. No further
discussion is required
Yes – foraging habitat
possibly affected by sheep
grazing
No - proposed action will
not alter aquatic habitat
structure
Yes – potential for disease
transmission with
domestic sheep, and
potential for forage
competition
Selecting Alternative 2 or 3
“may impact individual
wolverines but is not likely
to result in a loss of
viability on the planning
area, nor cause a trend to
federal listing or a loss of
species viability
rangewide”.
Selecting Alternative 2 or 3
will have “no impact” on
river otter. No further
discussion is required
Selecting Alternative 2 or 3
“may impact individual
bighorn sheep but is not
likely to result in a loss of
viability on the planning
area, nor cause a trend to
federal listing or a loss of
species viability
rangewide”.
No Selecting Alternative 2 or 3
will have “no impact” on
Spotted bat. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
Townsend’s big-eared bat. No
further discussion is
required
114

Species
Habitat Present In the
Silverton Landscape?
Yuma myotis (BLM) No – too high elevation, not
known to occur in San Juan Co.
Insects (1)
Great Basin silverspot
(FS)
No – too high elevation, not
known to occur in San Juan Co.
Reptiles (2)
Desert spiny lizard (BLM) No – no sparsely vegetated rocky
areas near flowing streams, not
known to occur in San Juan
County
Longnose leopard lizard
(BLM)
No – Landscape too high
elevation, not known to occur in
San Juan Co.
Table C-3. Forest Plan MIS species for the SJNF
Species or Habitat
Impacted by Action
Project Impact
Alternatives?
Determination
No Selecting Alternative 2 or 3
will have “no impact” on
Yuma myotis. No further
discussion is required
No Selecting Alternative 2 or 3
will have “no impact” on
Great Basin silverspot. No
further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
desert spiny lizard. No
further discussion is
required
No Selecting Alternative 2 or 3
will have “no impact” on
longnose leopard lizard. No
further discussion is
required
MIS Species Preferred Habitat Brought Forward for Detailed Analysis?
Birds (9)
Columbian sharp-tailed grouse
(Tympanuchus phasianellus
columbianus)
Reintroduced to non-federal lands near
Dolores by Colorado Division of Wildlife
in 2004. Currently not on Columbine or
Pagosa RD but Dolores RD may retain
habitat.
No, grouse was not analyzed further as SJNF MIS
because it has not been documented to occur on
the SJNF for decades and no habitat is present in
the Silverton Landscape.
Green-tailed towhee (Pipilo
chlorurus)
Gambel oak/mountain shrub, pinyonjuniper,
sagebrush, and riparian.
Spring-fall resident.
Yes, towhee habitat is present in the Landscape
and potentially affected by sheep grazing.
Hairy woodpecker (Picoides
villosus)
All forested habitats, associated with
snags for foraging and nesting. Yearround
resident.
No, woodpecker habitat is present in the Landscape
but nesting and foraging habitat will not be affected
by sheep grazing. No further analysis is necessary.
Mallard (Anas platyrhynchos)
Aquatic and riparian. Spring-fall resident
and winter migrant.
No, mallard habitat is present in the Landscape but
nesting and foraging habitat will not be affected by
sheep grazing. No further analysis is necessary.
No, turkey was not analyzed further as SJNF MIS.
Merriam’s turkey (Meleagris
gallopavo merriami)
Grass-forb meadows, ponderosa
pine/Gambel oak and open montane
forests, aspen. Year-round resident.
Turkey habitat is present in the landscape but
nesting and foraging habitat will not be directly
affected by sheep grazing. No further analysis is
necessary.
Mexican spotted owl (Strix
occidentalis lucida)
Mixed conifer habitat (Douglas-fir,
ponderosa pine, white fir) located in
steep rock-walled canyons. Only one
confirmed occurrence on the SJNF, in
late summer.
Early-successional, alpine, mature
No, spotted owl was not analyzed further as SJNF
MIS. Spotted owl has not been confirmed to breed
on the SJNF and no suitable habitat is present in the
Landscape. No further analysis is necessary.
Mountain bluebird (Sialia
currucoides)
aspen, mixed conifer, Gambel
oak/mountain shrub, pinyon-juniper,
ponderosa pine, and sagebrush, snag
and cavity-dependant. Spring-fall
resident.
Yes, bluebird habitat is present in the Landscape
and foraging habitat is potentially affected by sheep
grazing.
Northern goshawk (Accipiter
gentilis)
Mature deciduous, coniferous and
mixed forests. Spring-fall resident and
winter migrant.
No, goshawk was not analyzed further as SJNF
MIS. Goshawk habitat is present in the Landscape
but nesting and foraging habitat will not be affected
by sheep grazing. No further analysis is necessary.
115

MIS Species Preferred Habitat Brought Forward for Detailed Analysis?
Southwestern willow flycatcher
(Empidonax traillii extimus)
Fish (4)
Brook trout (Salvelinus fontinalis) Aquatic. Resident
Brown trout (Salmo trutta) Aquatic. Resident.
Colorado River cutthroat trout
(Oncorhynchus clarki pleuriticus)
Rainbow trout (Oncorhynchus
mykiss)
Insects (1)
Uncompahgre fritillary butterfly
(Boloria acrocnema) Endangered
Mammals (10)
Willow riparian with patch size 30 ft. x
30 ft. x 5 ft. tall, up to ¼ acre or larger.
Summer resident, only one regular
breeding location on the SJNF.
Aquatic. Resident.
Aquatic. Resident.
Snow willow located in alpine habitat.
Abert’s squirrel (Sciurus aberti) Ponderosa pine. Year-round resident.
American marten (Martes
americana)
Spruce-fir and cool-moist mixed conifer.
Year-round resident.
Beaver (Castor canadensis) Riparian/wetlands. Year-round resident.
Black bear (Ursus americanus) All forested habitats. Resident.
Canada lynx (Lynx canadensis)
Deer mouse (Peromyscus
maniculatus)
Elk (Cervus elaphus)
Mule deer (Odocoileus
hemionus)
Spruce-fir, cool-moist mixed conifer,
high elevation aspen mixed with sprucefir
or cool-moist mixed conifer, and
willow riparian adjacent to the above
habitats. Reintroduced to SJNF by
CDOW.
All forested and non-forested habitats.
Resident.
All terrestrial habitats; pine, pinyonjuniper
and mountain shrublands in
winter. Resident.
All terrestrial habitats; pine, pinyonjuniper,
and Gambel oak/mountain
shrublands in winter. Resident.
River otter(Lontra canadensis) Watercourses with fish. Resident.
No, not analyzed further as SJNF MIS. Flycatcher
habitat is present in the Landscape but sheep do not
regularly occur in the one habitat patch that is
suitable for flycatchers and livestock do not appear
to have any impact on its habitat structure. No
further analysis is necessary.
No, brook trout is not analyzed further as SJNF MIS.
Trout habitat is present in the Landscape but will not
be directly affected by sheep grazing. No further
analysis is necessary.
No, brown trout is not analyzed further as SJNF
MIS. Trout habitat is present in the Landscape but
will not be directly affected by sheep grazing. No
further analysis is necessary.
No, there are no conservation populations in the
Landscape.
No, rainbow trout is not analyzed further as SJNF
MIS. Trout habitat is present in the Landscape but
will not be directly affected by sheep grazing. No
further analysis is necessary.
No, UFB was not analyzed further as SJNF MIS.
Butterfly habitat is present in the Landscape but
project design criteria will prevent livestock grazing
impacts. No further analysis is necessary.
No, Abert’s squirrel was not analyzed further as
SJNF MIS. Squirrel habitat is present in the
Landscape but will not be affected by sheep
grazing. No further analysis is necessary.
No, marten was not analyzed further as SJNF MIS.
Marten habitat is present in the Landscape but will
not be affected by sheep grazing. No further
analysis is necessary.
No, beaver was not analyzed further as SJNF MIS.
Beaver habitat is present in the Landscape but will
not be directly affected by sheep grazing. No further
analysis is necessary.
No, bear was not analyzed further as SJNF MIS.
Bear habitat is present in the Landscape but will not
be affected by sheep grazing. No further analysis is
necessary.
Yes, lynx habitat is present in the Landscape and
primary prey is potentially affected by livestock
grazing.
No, mouse habitat is present in the Landscape but
their abundance and distribution is driven by climatic
conditions, not sheep grazing.
Yes, elk habitat is present in the Landscape and
food sources are potentially affected by sheep
grazing.
Yes, deer habitat is present in the Landscape and
food sources are potentially affected by sheep
grazing.
No, otter was not analyzed further as SJNF MIS.
Otter habitat is present in the Landscape but will not
be directly affected by sheep grazing. No further
analysis is necessary.
116

Table C-4. Migratory Bird Species List
Migratory birds that are listed on the FWS BCR 16 list, PIF PA 62 list, Colorado Listing of
Endangered, Threatened and Wildlife Species of Special Concern, and USFS Rocky Mountain
Region Sensitive Species List, BLM’s Colorado State Director’s Sensitive Species list, with
likelihood to occur in the Silverton Landscape.
Likelihood of
Species Status* Preferred Habitats Occurrence @
Season of
Occurrence Analysis Group
American Bittern FS Riparian/Wetlands (cattail Low N/A N/A – no suitable marshes
marsh)
in Landscape
American Dipper PIF Riparian/Wetlands (fast- High Breeding Riparian/Wetlands
moving streams)
Season
American Pipit PIF Alpine Tundra, cultivated High Breeding Alpine Tundra
agriculture
Season
American Three- FS Spruce-Fir, cool-moist High Year Round Cavity Constructors
toed Woodpecker
Mixed Conifer
Bald Eagle FS, State Riparian/Wetlands Low N/A N/A – no cottonwood
(cottonwood gallery
gallery forest, nesting or
forest), Grassland,
winter foraging habitat in
Sagebrush, Pinyon-
Juniper, Ponderosa Pine
Landscape
Band-tailed Pigeon PIF Ponderosa Pine Low N/A N/A - no suitable ponderosa
pine forest in Landscape
Black Swift FS, BCR, Riparian/Wetlands High Breeding Riparian/Wetlands
PIF (waterfalls)
Season
Black Tern BLM Riparian/Wetlands (cattail Low N/A N/A, not known to occur in
marsh)
San Juan County
Black-throated Gray BCR Pinyon-Juniper Low N/A N/A, not known to occur in
Warbler
San Juan County
Boreal Owl FS, PIF Spruce-Fir High Year Round Cavity Dependant
Brewer’s Sparrow FS, PIF Sagebrush Low N/A N/A, no suitable sagebrush
in Landscape
Broad-tailed PIF Mountain Shrub, Aspen, High Breeding Mixed-conifer
Hummingbird
Ponderosa Pine, Mixed
Conifer, Riparian/Wetland
Season
Brown-capped Rosy
Finch
PIF Alpine Tundra High Year Round Alpine Tundra
Columbian Sharp- FS, BLM, Mountain Shrub Low N/A N/A, not known to occur in
tailed Grouse State, MIS
San Juan County
Cordilleran
PIF Riparian/Wetlands High Breeding Riparian/Wetlands
Flycatcher
(canyon streams)
Season
Dusky Grouse PIF Mixed Conifer High Year Round Mixed-conifer
Ferruginous Hawk FS, BLM, Agricultural, Grasslands Low N/A N/A, not known to occur in
BCR, State
San Juan County
Flammulated Owl FS, BCR, Ponderosa Pine, mixed- High Breeding Mixed-conifer
PIF conifer
Season
Golden Eagle BCR Barren (rock cliffs),
Agricultural, Grasslands,
Alpine Tundra
High Year Round Cliff Nesters
Grace’s Warbler BCR, PIF Ponderosa Pine Low N/A N/A, not known to occur in
San Juan County
Gray Vireo BCR Pinyon-Juniper Low N/A N/A, not known to occur in
San Juan County
Green-tailed PIF, MIS Mountain Shrub,
Low N/A N/A, not known to occur in
Towhee
Sagebrush
San Juan County
Gunnison Sage FS, BLM, Sagebrush Low N/A N/A, not known to occur in
Grouse
BCR, ESA,
PIF, State
San Juan County
117

Likelihood of
Species Status* Preferred Habitats Occurrence @
Season of
Occurrence Analysis Group
Hairy Woodpecker MIS Ponderosa Pine, Mixed
Conifer, Spruce-Fir,
Aspen, Pinyon-Juniper,
Riparian/Wetlands
(cottonwood gallery
forest)
High Year Round Cavity Constructors
Hammond’s PIF Mixed Conifer, Spruce-Fir High Breeding Spruce-fir
Flycatcher
Season
Lazuli Bunting PIF Riparian/Wetlands High Breeding Riparian/Wetlands
(Riparian shrublands)
Season
Lewis’ Woodpecker FS, BCR, Ponderosa Pine,
Low N/A N/A no ponderosa pine or
PIF Riparian/Wetlands
cottonwood gallery forest
(cottonwood gallery
forest)
in Landscape
Loggerhead Shrike FS Agriculture, Pinyon- Low N/A N/A, no sagebrush or
Juniper Sagebrush,
suitable shrublands in
Landscape
MacGillivray’s PIF Riparian/Wetlands High Breeding Riparian/Wetlands
Warbler
(Riparian shrublands)
Season
Mallard MIS Riparian/Wetlands (lakes High Breeding Riparian/Wetlands
and rivers)
Season
Merriam’s Turkey MIS Ponderosa Pine, Mixed Moderate Breeding Mixed-conifer
Conifer, Grasslands,
Aspen, Mountain Shrub
Season
Mexican Spotted ESA, PIF, Mixed Conifer Low N/A N/A, not known to occur in
Owl
State, MIS
San Juan County
Mountain Bluebird MIS Ponderosa Pine, Mixed High Breeding Cavity Dependant
Conifer, Spruce-Fir,
Aspen, Pinyon-Juniper,
Sagebrush, Grasslands
Season
Northern Goshawk BLM, MIS Ponderosa Pine, Mixed
Conifer, Spruce-Fir,
Aspen
High Year Round Spruce-fir
Northern Harrier FS, BCR Agricultural,
Low N/A N/A – no suitable wetlands
Riparian/Wetlands (cattail
or cattail marshes in
marsh)
Landscape
Olive-sided FS, PIF Mixed Conifer, Ponderosa High Breeding Spruce-fir
Flycatcher
Pine, Spruce-Fir
Season
Peregrine Falcon BLM, Barren (rock cliffs) Moderate Breeding Cliff Nesters
BCR, State
Season
Pinyon Jay BCR Pinyon-Juniper Low N/A N/A, not known to occur in
Prairie Falcon BCR Barren (rock cliffs),
Grasslands
High Breeding
Season
San Juan County
Cliff Nesters
Purple Martin FS, PIF Aspen Low N/A N/A, not known to occur in
San Juan County
Red-naped
PIF Aspen High Breeding Cavity Constructors
Sapsucker
Season
Sage Sparrow BCR, PIF Sagebrush Low N/A N/A, not known to occur in
San Juan County
Short-eared Owl FS, BCR, Agricultural,
Low N/A N/A – no suitable wetlands
PIF Riparian/Wetlands (cattail
or cattail marshes in
marsh)
Landscape
Southwestern ESA, State, Riparian/Wetlands Low N/A N/A, not known to occur in
Willow Flycatcher MIS (Riparian shrublands)
San Juan County
Swainson’s Hawk BCR Agricultural Low N/A N/A, not known to occur in
San Juan County
Violet-green PIF Aspen, Ponderosa Pine, High Breeding Cavity Dependant
Swallow
Barren (rock cliffs)
Season
Virginia’s Warbler BCR, PIF Mountain Shrub Low N/A N/A no Gambel oak or
mountain shrub
communities Landscape
118

Likelihood of
Species Status* Preferred Habitats Occurrence @
Season of
Occurrence Analysis Group
Western Burrowing FS, BCR, Grasslands (prairie dog Low N/A N/A, not known to
Owl
State colonies)
regularly occur in San Juan
County
White-faced Ibis FS, BLM Agricultural,
Low N/A N/A, not known to occur in
Riparian/Wetlands
(mudflats)
San Juan County
White-tailed
Ptarmigan
FS, PIF Alpine Tundra High Year Round Alpine Tundra
Willet PIF Riparian/Wetlands Low N/A N/A, not known to occur in
(mudflats)
San Juan County
Williamson’s BCR, PIF Ponderosa Pine, Mixed High Breeding Cavity Constructors
Sapsucker
Conifer, Spruce-Fir
Season
Wilson’s Phalarope BCR Riparian/Wetlands (lakes) Low N/A N/A, not known to occur in
San Juan County
Wilson’s Warbler PIF Riparian/Wetlands High Breeding Riparian/Wetland
(Riparian shrublands)
Season
Western Yellow- FS, BLM, Riparian/Wetlands Low N/A N/A, not known to occur in
billed Cuckoo BCR, ESA, (cottonwood gallery
San Juan County
Status Codes*:
State forest)
BCR = On Bird Conservation Region 16 (Southern Rockies/Colorado Plateau) Birds of Conservation Concern List (USDI FWS 2002).
BLM = On USDI Bureau of Land Management Colorado Bureau of Land Management Sensitive Fish and Wildlife Species List (USDI
BLM 2000). Effects to the species were analyzed in the Biological Evaluation.
ESA = Listed under the federal Endangered Species Act of 1973 as Threatened, Endangered, Proposed or Candidate for federal listing and
known or likely to occur or have habitat on lands administered by the SJFO (USDI FWS 2005). Effects to the species were
analyzed in the Biological Assessment.
FS = On USDA Forest Service Rocky Mountain Region (Region 2) Regional Forester’s Sensitive Species List (USDA FS 2003). Effects to
the species were analyzed in the Biological Evaluation
MIS = Management Indicator Species for the San Juan National Forest. Effects to the species were analyzed in a Wildlife Report.
PIF = On Colorado Partners in Flight Physiographic Area 62 List (Beidleman 2000).
State = On Colorado Division of Wildlife’s Listing of Endangered, Threatened and Wildlife Species of Special Concern (CDOW 2007).
Likelihood of Occurrence @ :
High = Species is known or thought likely to occur in the project area during either breeding or non-breeding seasons due to documented
occurrence or presence of suitable habitat. Species may occur in small numbers or in widely distributed areas.
Moderate = May occur in the project area during some years, but is unlikely to breed due to lack of habitat. Or, occurrence in the project
area is irregular and unpredictable and during the non-breeding season only.
Low = Species is not known or thought likely to breed or winter in the project area due to lack of suitable habitat.
119

APPENDIX D – BIGHORN RISK ASSESSMENT
See Next Page
120

Silverton Grazing Risk Assessment
Assessment of Risk of Physical Contact between Rocky Mountain Bighorn
Sheep and Domestic Sheep in the Silverton Grazing Analysis Landscape
INTRODUCTION
The Silverton Landscape is located in San Juan and La Plata Counties around the town of
Silverton, Colorado, encompassing much of the headwaters of the Animas River basin (see
Figures 1 and 2, below). Federal lands in the Silverton Landscape are managed by the
Columbine Field Office of the BLM and Columbine Ranger District of the San Juan
National Forest.
The Silverton Landscape includes about 195,050 acres, of which about 32,099 acres
(16%) is Bureau of Land Management (BLM) land, 142,994 acres (73%) is National Forest
System (NFS) land, 18,670 acres (10%) is Private land, and 1,287 acres (

Silverton Grazing Risk Assessment
The current San Juan National Forest Land and Resource Management Plan of 1983
(Forest Plan), amended in 1992, and the BLM’s San Juan/San Miguel Resource
Management Plan of 1984 (RMP), along with Allotment Management Plans (AMP) and
Grazing Permits, regulate the current numbers and type of livestock, dates of use,
salting, vegetation manipulation and other activities undertaken for the purpose of
grazing domestic livestock on public lands.
Domestic Sheep are the only livestock permitted to graze in this landscape, and their
principle forage areas are in the alpine zone. Alpine rangelands have been used for
grazing domestic sheep in this Landscape since the late 1800’s. Prior to government
control, sheep were herded in tightly grouped bands and continuously bedded in the
same location for several nights in a row, which resulted in large forage losses and soil
damage from trampling and excessive trailing. Some sites in the Silverton Landscape still
display these historic effects. There are no additional bands of domestic sheep being
grazed on adjacent or intermingled non-federal lands, in addition to the bands permitted
to graze on the Federal allotments under analysis in this document.
Rocky Mountain bighorn sheep are native to the Silverton Landscape. Desert bighorn
sheep are not known or thought likely to occur in the Landscape. For this reason, this
analysis refers only to Rocky Mountain bighorn sheep.
One of the primary management concerns associated with domestic sheep grazing in the
Silverton Landscape is the potential for physical contact between domestic sheep and
bighorn sheep. This contact increases risk of subsequent bighorn sheep mortality events
and reduced recruitment, primarily due to respiratory diseases (Western Association of
Fish and Wildlife Agencies 2007). The complete range of mechanisms and/or causal
agents that lead to disease events in bighorn sheep is still under debate, and not all
bighorn sheep disease events can be attributed to contact with domestic sheep (Colorado
Division of Wildlife 2009, Aune et al. 1998, Onderka and Wishart 1984). However, when
contact between wild sheep and domestic sheep and goats has been documented, the
severity of the wild sheep die-off is typically more pronounced (Aune et al. 1998, Martin et
al. 1996). For these reasons, it is prudent to implement management actions designed to
reduce or eliminate the potential for contact between wild sheep and domestic sheep
(Colorado Division of Wildlife 2009, Western Association of Fish and Wildlife Agencies
2007).
This “Risk Assessment” analysis is focused on the “risk of contact” between bighorn sheep
and domestic sheep. No presumption is made that contact will lead to disease
transmission or a subsequent bighorn sheep mortality event. However, the assumption is
made that physical contact between bighorn sheep and domestic sheep results in an
increased risk to bighorn sheep of disease transmission and therefore it is prudent to
reduce the risk of contact and/or increase the distance and/or degree of effectiveness of
separation between the two species (Colorado Division of Wildlife 2009, Western
Association of Fish and Wildlife Agencies 2007, USDI Bureau of Land Management 1998).
The goal of this “Risk Assessment” is to provide the decision maker with an objective
evaluation of the risk of contact between bighorn sheep and domestic sheep in each active
and each vacant domestic sheep grazing allotment in the Silverton Landscape. The
decision maker will then use the results of this “Risk Assessment” as an important factor
of consideration in their decision regarding domestic sheep grazing in the Silverton
Landscape.
D-2

Silverton Grazing Risk Assessment
MANAGEMENT PRACTICES
The documents described below provide suggestions for consideration by land
management agencies evaluating domestic sheep grazing activities within or in proximity
to wild sheep range. These documents provide recommendations similar to “best
management practices” and as such are not required. However, as generally accepted
principles for achieving consensus based conservation of bighorn sheep, these documents
provide key concepts that can help land management agencies achieve species
conservation goals. All of these documents were reviewed and key concepts were
considered in the development of project design criteria for the Silverton Landscape.
These concepts were also considered in the development of this Risk Assessment.
• Instruction Memorandum 98-140 (USDI Bureau of Land Management): provides
guidelines for BLM Field Offices in the western United States for the management
of domestic sheep in occupied bighorn sheep range on BLM lands. The guidelines
provide “a balanced approach” for management of domestic sheep in native wild
sheep habitats, and should be followed whenever reintroductions, transplants, or
augmentations of wild sheep populations, or proposed changes in a livestock
grazing permit on BLM administered lands are being considered. This IM expired
on September 30, 1999 and has not been updated or replaced. Although this IM
has expired, we believe the management actions proposed in Alternative 3 are
consistent with the content of this IM.
• A Process for Finding Management Solutions to the Incompatibility Between
Domestic and Bighorn Sheep (Schommer and Woolever 2001): provides Forest
Service staff with recommendations for using a collaborative approach to find
management solutions to reduce or eliminate contact between wild sheep and
domestic sheep. We believe the process used and solutions proposed in Alternative
3 are consistent with the recommendations of this report.
• Colorado Bighorn Sheep Management Plan (George et al. 2008): adopted in 2009,
directs CDOW to, among other things, prioritize conservation of bighorn sheep
herds in Colorado on the basis of herd size, native status, management history,
and potential for interaction with domestic sheep. State management goals for the
bighorn sheep herds affected by this project were considered by local CDOW staff
that provided information regarding affects this project might have on bighorn
sheep.
• Memorandum of Understanding (Colorado Division of Wildlife 2009): signed in
March of 2009 by Forest Service Rocky Mountain Region, Bureau of Land
Management Colorado State Office, Colorado Division of Wildlife, Colorado
Department of Agriculture, and the Colorado Woolgrowers Association. This
document recognizes, among other things, that contact between domestic sheep
and bighorn sheep increases the probability of respiratory disease outbreaks in
bighorn sheep, but not all outbreaks can be attributed to contact with domestic
sheep. The goal is to minimize contact by decreasing the opportunities for
domestic/bighorn sheep interaction; while still recognizing that some vacant sheep
allotments are important to the domestic sheep industry as forage reserves or for
other economic or management reasons.
• Western Association of Fish and Wildlife Agencies Wild Sheep Report (WAFWA
2007): a report published by a collection of state and provincial wildlife
management agencies that seeks to work collaboratively with livestock industry to
reduce the potential for wild sheep die-offs. This report articulates concerns about
potential disease transmission between domestic livestock and wildlife, and
suggests an array of management approaches to minimize such risks. This report
D-3

Silverton Grazing Risk Assessment
advocates, among other things, that effective separation (both temporal and/or
spatial) of wild and domestic sheep should be a primary management goal.
Effective separation does not necessarily require the removal of domestic sheep.
AFFECTED BIGHORN SHEEP HERDS
The Silverton Landscape intersects the mapped summer range of two bighorn sheep
herds, S33, the Pole Mountain/Upper Lake Fork Herd, and S71, the West Needles Herd.
The S33 bighorn herd is considered by CDOW to represent one large meta-population
with S21, the Ouray/Cow Creek herd, to the north and west. There is no mapped overlap
between domestic sheep allotments in the Silverton Landscape and mapped summer
range for S21, although S21 mapped summer range is about 5 air miles to the north of
the Picayne/Mineral Point Allotment. For this reason, there is a possibility that decisions
about domestic livestock grazing in the Silverton Landscape could have indirect effects on
the S21 Ouray/Cow Creek bighorn sheep herd. The level of risk to S21 from this indirect
effect is thought to be low compared to the direct effect of domestic sheep grazing within
much closer proximity, and in direct overlap with mapped summer range for S21,
currently permitted by the Ouray Ranger District of the Uncompahgre National Forest,
and the Gunnison Field Office of the BLM.
One of the alternatives that was considered but dismissed from further analysis
suggested moving domestic sheep from “High Risk” allotments in the Silverton Landscape
to one or more of 6 currently vacant allotments along the Vallecito Creek drainage in the
Weminuche Wilderness. The 6 allotments in the Vallecito Creek drainage all either overlap
with mapped summer range of the S28 Vallecito Creek bighorn sheep herd, or the stock
driveways that are necessary for ingress/egress to these 6 allotments overlap with
mapped summer range. Therefore, this suggestion could have resulted in indirect effects
to the S28 Vallecito Creek bighorn sheep herd. The risk of indirect effects to S28 are low
because this alternative was considered but dismissed from further analysis (see
discussion below).
There is about 41,430 acres of mapped overlap in the Silverton Landscape between the
summer range of these two bighorn sheep herds and active and vacant domestic sheep
grazing allotments. It is apparent however, that most domestic sheep grazing and trailing
activities in the Silverton Landscape occurs outside of currently mapped bighorn sheep
summer range. Because domestic sheep are only present in the Landscape during
summer, generally the months of July and August, the following Risk Assessment
analysis will focus on overlap between domestic sheep grazing allotments and mapped
summer range and summer concentration areas for bighorn sheep. Mapped bighorn
winter range, winter concentration areas, and production areas were not considered in
this analysis because domestic sheep are not present in the landscape during winter or
spring. If CDOW data suggested sufficient bighorn occurrence during summer months on
the areas mapped as winter range or production areas, those areas were also mapped by
CDOW as summer range or summer concentration areas. Conversely, bighorn occurrence
outside of mapped summer range is irregular and unpredictable and therefore the
concern for contact between domestic sheep and bighorn sheep outside of mapped
summer range is low.
Pole Mountain/Upper Lake Fork Herd (S33):
The 2007 estimated population size of the Pole Mountain/Upper Lake Fork Herd was
about 90 animals (George et al. 2008). Although not well documented, evidence from the
Colorado Division of Wildlife (Diamond 2005) suggests that the S33 Pole Mountain/Upper
Lake Fork Herd experienced a significant and widespread die-off in the late 1980’s. No
D-4

Silverton Grazing Risk Assessment
specific disease monitoring has occurred in S33, nor have these sheep ever been treated
with fenbendazole. Based on the high level of recruitment observed in S33, it appears that
this bighorn sheep herd is not experiencing any additive mortality from predation. Habitat
quality in the unit is excellent (Beecham et al. 2007).
Monitoring by the Colorado Division of Wildlife, along with recent (2009) sighting reports
indicate this herd is in an expansion phase (Wait pers. comm.). CDOW believes it is likely
that individual bighorns from S33 may pioneer into historic range as the population
increases. If so, dispersal and range expansion may result in bighorns filling vacant
habitat and occupying areas where they have not been documented in recent years,
potentially placing S33 at an increased risk for contact with domestic sheep in nearby
active allotments.
S33 is recognized by the CDOW as comprising one large meta-population with S21, the
Ouray-Cow Creek Herd, to the north and west. Together, this meta-population is
estimated to be over 200 animals in size. There is no direct overlap between domestic
sheep allotments in the Silverton Landscape and mapped summer range for the S21
Ouray/Cow Creek herd. Within S33, there are 3 historic subpopulations of bighorn sheep
(Diamond 2005). These subpopulations are commonly referred to as the Pole Mountain
herd, the Upper Lake Fork herd, and the Henson Creek herd. Exchange is likely to occur
among these three subpopulations throughout the year.
S33 is considered by CDOW to be an indigenous herd of > 100 animals and comprised of
one or more interconnected herds. For this reason, the recently adopted Colorado Bighorn
Sheep Management Plan (George et al. 2008) designates S33 as a primary (“Tier 1”)
population and ranked as a high priority for conservation at a statewide level. This
designation places S33 in the top priority for inventory, habitat protection and
improvement, disease prevention, and research. These primary core populations are
thought to represent those populations that have maintained the greatest genetic
diversity, and their ranges may represent habitats where bighorn populations have best
been able to persist in sizable numbers. As such, CDOW considers S33 to be among the
most important bighorn herds in the state. For this reason, CDOW recommends taking all
available opportunities to reduce the potential for disease transmission from domestic
sheep to this herd.
Records indicate the S33 herd has been supplemented with animals from other herds at
least three times in the recent past. In 1987 there was a release on Pole Mountain of 3
animals from the Trickle Mountain herd, and a release on Upper Lake Fork of 2 animals
from the San Luis/Cebolla herd. Several animals from the Georgetown herd released in
the Animas River canyon in 2000 through 2003 were later observed in residence in the
S33 herd.
The CDOW continues to manage S33 for providing hunting opportunities. Between 1982
and 1990 CDOW issued between 2 and 5 ram tags annually. S33 was closed to hunting
between 1991 and 2005, then re-opened for hunting in 2006 with 3 ram tags issued
annually since then. Hunting success rate averages 30% for this unit (Diamond 2005). No
ewe licenses have ever been issued for this herd.
Under current management, the S33 bighorn herd overlaps with 3 active or vacant
domestic sheep allotments: Picayne/Mineral Point (active), Eureka (active), and Minnie
Gulch (vacant). All sheep grazing allotments that overlap with S33 summer range are
BLM allotments. No FS grazing allotments in the Silverton Landscape overlap with S33
D-5

Silverton Grazing Risk Assessment
bighorn summer range. Together, there is about 4,877 acres of overlap between these
allotments and mapped summer range of the S33 herd. Within this area of overlap, about
821 acres (17%) are suitable for domestic sheep grazing.
West Needles Herd (S71):
The S71 West Needles Herd was established with animals translocated from the
Georgetown Herd in 2000, and 2002-2003. The 2007 estimated population size of the
West Needles herd was 75 animals (George et al. 2008), and reproduction and survival
have been good (Beecham et al. 2007). Bighorn sheep use the entire Animas River canyon
from Rockwood up to Needle Creek. The primary summer range of this herd is the West
Needle Mountains, and primary winter and lambing range is the Animas River canyon
from Rockwood up to the Cascade Wye.
Immediately after release, two bighorns dispersed into the S21 Ouray-Cow Creek herd.
Based on ear tag observations, several sheep dispersed into the S33 Pole Mountain/Upper
Lake Fork herd. Six or seven sheep moved into the Hermosa Cliffs area to the west of the
Animas River canyon and have remained there and produced lambs every year.
The CDOW opened S71 for hunting for the first time in 2007 with 1 ram tag issued
annually. No ewe licenses have ever been issued for this herd.
S71 is considered a translocated herd by CDOW and therefore is lower priority for
conservation at a statewide level (George et al. 2008). As a translocated population,
CDOW recognizes the existence of pre-existing domestic sheep grazing to the north, east,
and west of S71, and does not advocate closure of active domestic sheep allotments on
public land based solely on the potential for interaction between domestic and bighorn
sheep (Colorado Division of Wildlife 2009). CDOW does however, suggest working with
existing permittees grazing sheep in areas of mapped overlap with bighorn sheep summer
range to collaboratively take advantage of opportunities if/when they arise to reduce the
potential for physical contact, and the subsequent potential for disease transmission,
between domestic sheep and bighorn sheep of the S71 herd.
Under current management, the S71 bighorn herd overlaps with 6 active or vacant
domestic sheep allotments. Of these, 5 are FS allotments: West Lime (vacant), Little
Molas/West needles (vacant), Needles Mountains (vacant), Flume (vacant), and Deer
Creek/Engine Creek (active). One active BLM grazing allotment, Gladstone, overlaps with
mapped summer range for S71. Together, there is about 36,554 acres of overlap between
these 6 allotments and mapped summer range of the S71 herd. Within this area of
overlap, about 9,464 acres (26%) is suitable for domestic sheep grazing.
ALTERNATIVES CONSIDERED BUT ELIMINATED FROM FURTHER ANALYSIS
We considered the possibility of moving domestic sheep bands from currently active
allotments where the perceived risk of contact with bighorn sheep is “High” (see figure 3,
below) to other currently vacant allotments where the perceived risk of contact with
bighorns may be lower. Below is a brief discussion of the alternatives considered but
eliminated, and the reasons for their elimination.
Graysill and Flume allotments (FS, vacant allotments): These allotments have been vacant
since 1989. They have been successfully used as a forage reserve as recently as 2002 with
no adverse impacts to vegetation and soils. There are few if any conflicts with recreation.
There is a small area of overlap with mapped summer range of the S71 West Needles
bighorn sheep herd in the extreme south end of the Flume Allotment. Due to difficult
D-6

Silverton Grazing Risk Assessment
access, potential conflicts with a summer home group, and generally steep slopes with
potentially sensitive soil types, we recommend these allotments be placed into forage
reserve status. When active however, all of the project design criteria and adaptive
management practices for active allotments should be applied to these allotments. We
anticipate these allotments may be used once per 15 years in an emergency situation,
such as the Missionary Ridge fire of 2002. Restocking with a full band of domestic sheep
annually is likely to create new adverse impacts to soils and vegetation. For these
reasons, we recommend maintaining Graysill and Flume allotments in forage reserve
status at this time and not restocking on an annual basis.
Little Molas-West Needles (BLM & FS, vacant allotment): This allotment has been in nonuse
for many years and became officially vacant in 2007. We recommend the closing of
this allotment for its close proximity and large area of overlap with mapped summer range
and summer concentration areas with the S71 West Needles bighorn sheep herd. Almost
the entire allotment overlaps with mapped bighorn sheep summer range. Much of the
area of overlap is known to be regularly used by bighorn sheep in summer. If this
allotment were to be restocked with domestic sheep, the potential for contact with bighorn
sheep appears to be high. Moving domestic sheep from another allotment to the Little
Molas-West Needles Allotment would be moving sheep to an area of equal or greater risk
for contact with bighorn sheep. Under Alternative 3, the portions of this allotment west of
U.S. Highway 550 that do not overlap with mapped bighorn summer range are
incorporated into the active Engine Creek/Deer Creek allotment. For these reasons, we
recommend closing the Little Molas-West Needles Allotment.
West Lime (FS, vacant allotment): The West Lime allotment has been in non-use for many
years and became officially vacant in 2007. While this allotment has sufficient capacity
and is in good ecological condition, bighorn rams have recently expanded into western
portions of this allotment during summer, overlapping with the domestic sheep grazing
season. High recreation activity in the entire South Mineral Creek drainage makes
domestic sheep ingress and egress to this allotment difficult and highly contentious.
Several modifications to the boundaries of this allotment were proposed to remove areas
of potential bighorn sheep overlap and to also avoid high use recreation areas. However,
all reasonable options for boundary adjustments left insufficient capacity remaining to
sustain a band of domestic sheep for a viable grazing season without creating new
adverse impacts to soils and vegetation, as well as likely conflicts with popular recreation
use areas. For these reasons, we recommend closing the West Lime Allotment.
Minnie Gulch (BLM, vacant allotment): The Minnie Gulch allotment is believed to have
been vacant since 1983, although incidental use has occurred occasionally. This
allotment is managed in conjunction with the Cottonwood Allotment administered by the
Gunnison Ranger District of the Gunnison National Forest. Almost the entire allotment
overlaps with mapped bighorn sheep summer range. Bighorn sheep are reported to use
this allotment and it is in very close proximity to areas thought to be regularly used
bighorn summer range with habitat and terrain in between providing a natural extension
from the summer range areas into the Minnie Gulch Allotment. If this allotment were to
be restocked with domestic sheep, potential for contact with bighorn sheep appears to be
high. Moving domestic sheep from another allotment in the Landscape to the Needles
Mountains Allotment would be moving sheep to an area of equal or greater risk for
contact with bighorn sheep. We recommend the closing the Minnie Gulch Allotment for its
close proximity and large area of overlap with mapped summer range of the Pole
Mountain/Upper Lake Fork bighorn sheep herd (S33).
D-7

Silverton Grazing Risk Assessment
Needles Mountains (FS, vacant allotment): There are no records of any permitted livestock
being grazed on this allotment. Very little suitable domestic sheep range exists in the
allotment due to generally steep and rugged mountainous terrain. In addition, there are
very limited access routes into the allotment. There is a large area of overlap with mapped
summer range, summer concentration, and winter range areas with the S71 West Needles
bighorn sheep herd. If this allotment were to be restocked with domestic sheep, potential
for contact with bighorn sheep appears to be high. Moving domestic sheep from another
allotment in the Landscape to the Needles Mountains Allotment would be moving sheep to
an area of equal or greater risk for contact with bighorn sheep. For this reason, we
recommend closing the Needles Allotment.
Fall Creek, Johnson Creek, Leviathan, Rock Creek, Cave Basin, and Flint Creek (FS,
vacant allotments): These six allotments are all outside the Silverton Landscape. Five of
the six allotments have not been grazed by domestic sheep since 1974. The Cave Basin
Allotment was last grazed by sheep in 1988. They were vacated largely due to their
location in remote areas of the Weminuche Wilderness with difficult access, and their
relatively small size for a sustainable season of grazing. All of these allotments would have
a high potential for contact with bighorn sheep, either by overlap with or close proximity
to mapped bighorn summer range of the S28 Vallecito Creek bighorn sheep herd, or by
overlap or close proximity with their associated stock driveways necessary for
ingress/egress of domestic sheep bands. There have been few requests from the domestic
sheep industry to use these remote areas. There is a slight possibility that if several of
these allotments were combined, a logical grazing unit could be developed and managed
effectively. However, the high potential for contact with the S28 bighorn herd would likely
remain and would be difficult to mitigate. Moving domestic sheep from the Silverton
Landscape to any one or combination of these six allotments would be moving sheep to an
area of equal or greater risk for contact with bighorn sheep. For these reasons we
recommend these seven allotments not be considered for restocking with domestic sheep
from active allotments in the Silverton Landscape.
Pine River Allotment (FS, vacant allotment): This is a large vacant allotment that includes
much of the headwaters of the Pine River in the central Weminuche Wilderness. This
allotment has been vacant since 1980. This allotment has been vacant largely due to its
remote location in the central Weminuche Wilderness and the requirement to trail
animals a long distance via the Pine-Piedra Stock Driveway. There is substantial summer
recreation in the Granite Lake, Snowslide Canyon, Rincon La Vaca, and Rincon La Osa
portions of this allotment, and the Continental Divide Trail parallels the boundary of this
allotment for a number of miles.
There is substantial overlap between the Pine River Allotment and mapped summer range
of the S16 Cimmarona/Hossick bighorn sheep herd, including all of Snowslide Canyon.
Mapped bighorn summer range for S16 extends from the headwaters of the Piedra River
drainage west to the Pine River at the mouth of Rincon La Osa, making domestic sheep
access to or from the Pine River very difficult without passing through mapped bighorn
sheep summer range. In addition, the Rincon La Osa portion of the Pine River Allotment
is within 1 to 2 air miles of mapped summer range of the S28 Vallecito Creek bighorn
sheep herd.
Historic livestock ingress/egress to the Pine River Allotment was from the south along the
Pine-Piedra Stock Driveway, or along the Pine River Trail from Vallecito Reservoir. Both of
these routes pass through the heart of the S28 Vallecito Creek bighorn sheep herd’s
summer range and summer concentration area. The Pine River Trail is an extremely
D-8

Silverton Grazing Risk Assessment
popular summer recreation trail and is the main access route for hikers and horseback
riders into the central Weminuche Wilderness and the Pine River basin. Re-opening the
Pine-Piedra Stock Driveway for use by sheep would require a significant amount of
mechanical work, including moving large amounts of downed logs that were placed across
the trail as fireline mitigation after the 2002 Missionary Ridge wildfire.
To prevent having to trail domestic sheep up the Pine River trail and through the heart of
the S28 Vallecito Creek bighorn sheep herd’s summer range and summer concentration
area, or up the lengthy Pine Piedra Stock Driveway, it was proposed to access the Pine
River Allotment from the north via Rio Grande Reservoir. The proposal was to truck
domestic sheep to Rio Grande Reservoir, then trail sheep up the Weminuche Trail, south
over Weminuche Pass, and into Rincon La Vaca and Rincon La Osa. Sheep would then be
trailed back out via the Pine River Trail, over Weminuche Pass and back down to Rio
Grande Reservoir. We were unable to obtain permission from the Rio Grande National
Forest to use this access route. This route would take sheep through and very close to
mapped summer range for the S16 Cimmarona/Hossick herd.
If the Pine River Allotment were to be restocked with domestic sheep, potential for contact
with bighorn sheep from the S16 Cimmarona/Hossick herd and the S28 Vallecito Creek
herd appears to be high. Moving domestic sheep from a “High Risk” allotment in the
Silverton Landscape to the upper Pine River Allotment would be moving sheep to an area
of equal or greater risk for contact with bighorn sheep, thereby maintaining the same
problem, just moving it to a different location. We recommend not stocking any portion of
the Pine River Allotment due to its lengthy wilderness access route, lack of permission for
access from Rio Grande Reservoir, substantial overlap with mapped summer range for the
S16 Cimmarona/Hossick bighorn sheep herd, and need to trail through mapped summer
range of the S28 Vallecito Creek bighorn sheep herd.
RISK ASSESSMENT PROCESS
This “Risk Assessment” process involved the participation by FS/BLM wildlife biologists,
FS/BLM rangeland management specialists, FS/BLM decision makers, Colorado Division
of Wildlife terrestrial biologists and District Wildlife Managers, and domestic livestock
permittees. A series of meetings were held to review maps of the affected bighorn sheep
herds and grazing allotments.
The focus of the risk assessment process was on active and vacant domestic sheep
allotments (see Figures 2 and 3, below). Because vacant allotments could be restocked
administratively at any time, it is important to provide a risk rating in the event the
allotment was to be restocked. Allotments that have already been closed were not
specifically reviewed but would have received a rating of low risk.
The risk of physical contact between domestic sheep and bighorn sheep, with the
potential for subsequent disease transmission, was given a rating of “High’, “Moderate”, or
“Low”. Disease transmission however, is considered a correlate of contact, not an effect.
And, although disease transmission is discussed in this assessment, these ratings are not
intended to be an estimate of disease transmission probability, only an estimate of
relative level of risk for physical contact between domestic and bighorn sheep.
A risk rating of “High” indicates that contact between domestic sheep and bighorn sheep
is thought to be likely in the immediate future, although disease transmission resulting in
a bighorn sheep mortality event is by no means certain. If allotments have been operated
for many years without apparent disease transmission, we do not use this observation to
D-9

Silverton Grazing Risk Assessment
infer a lower risk rating. The fact that contact has not been observed, or a bighorn disease
event has not been detected, does not imply a lower risk for such events happening in the
future. For this reason, the allotment would still receive a rating of “High Risk”. A rating
of “Moderate Risk” indicates that physical contact between bighorn and domestic sheep
may occur at some point in the future, but effective separation may be achieved and/or
maintained for many years. The risk of physical contact between bighorn and domestic
sheep, with the subsequent potential for a bighorn disease outbreak, is thought to be
substantially less than for allotments in the “High Risk” category. Factors that reduce the
apparent risk of contact could include: application of herding techniques, bighorn sheep
distribution patterns, presence of towns, presence of habitat features that act as barriers
to bighorn sheep movement (Schommer and Woolever 2001). A rating of “Low Risk”
indicates that physical contact between domestic and bighorn sheep is believed to be
unlikely or irregular and unpredictable with the subsequent potential for a bighorn
disease outbreak thought to be unlikely or unpredictable in the future under the current
circumstances.
Where overlap exists between active domestic sheep allotments and mapped bighorn
sheep summer range or summer concentration areas (see Figures 1 and 2, below), the
risk of contact between domestic sheep and bighorn sheep, with the potential for
subsequent disease transmission, is “High” (see Figures 3 and 4, below). In vacant
allotments, the risk of contact is “Low” when the allotment is vacant, but becomes “High”
when the allotment is restocked.
Where overlap exists between active domestic sheep allotments and mapped bighorn
sheep summer range but domestic sheep are not actively grazed in that portion of the
allotment, the risk of contact between domestic sheep and bighorn sheep, with the
potential for subsequent disease transmission, may be either “High” or “Moderate”,
depending on the circumstances. The risk level assigned to the allotment depends on
whether or not there are mitigating factors such as distance to actively grazed portions of
the allotment, terrain features providing separation, presence of broad bands of dense
forest or presence of towns providing barriers to bighorn sheep movement, etc.
A risk rating of “High” could be mitigated down to a rating of “Moderate” with the
application of design criteria, changes in domestic sheep herding practices, not grazing
certain portions of the allotment, application of design criteria designed to reduce the
potential for contact, etc.
After assigning an initial risk rating, additional factors from the list provided below were
considered and a determination was made whether to change the initial risk rating.
Factors such as the application of project design criteria differ between Alternative 2 and
Alternative 3, leading to potentially different risk ratings for the same allotment among
the two alternatives.
D-10

Silverton Grazing Risk Assessment
FACTORS CONSIDERED IN THE RISK ASSESSMENT PROCESS
• Bighorn sheep mapped summer range and summer concentration areas (provided
by the Colorado Division of Wildlife):
o Summer range is that part of the overall range where 90% of individual
bighorn sheep are located between spring green-up and the first heavy
snowfall. Summer range is not necessarily exclusive of winter range; in some
areas winter range and summer range may overlap. Summer range does not
necessarily include all occurrences during the summer season.
o Summer concentration areas are those areas where bighorn sheep
concentrate from mid-June through mid-August. High quality forage,
security, and lack of disturbance may be characteristic of these areas to
meet the high energy demands of lactation and lamb rearing.
o Mapped production areas were not considered because there is no overlap
between them with active or vacant allotments in the Silverton Landscape.
Mapped winter range areas were not considered because domestic sheep are
not in the allotments during winter.
• Domestic sheep allotment activity status (FS and BLM);
• Changes in allotment boundary configuration (FS and BLM);
• Domestic sheep grazing suitability maps (FS and BLM);
• Vegetation types and topographic features within the allotment (FS and BLM);
• Colorado Division of Wildlife local staff’s professional opinions (District Wildlife
Managers and Terrestrial Biologists);
• FS and BLM local staff’s professional opinions (Wildlife Biologists, Range
Management Specialists, NEPA Specialists, Decision Maker);
• Domestic sheep permittees’ herding practices and bighorn sheep observations;
• Project Design Criteria (see Table 3 attached at the end of this document).
RISK ASSESSMENT OUTCOMES
This Risk Analysis found overlap between mapped summer ranges for wild bighorn sheep
and 8 domestic sheep grazing allotments in the Silverton Landscape (see Figures 1 and 2,
below). The analysis and findings for each allotment and alternative will be discussed
individually and are displayed below in Figures 3 and 4.
Engine Creek/Deer Creek Allotment (FS, active allotment):
Under current management, there is about 2,978 acres of overlap in the allotment with
mapped summer range of the S71 West Needles bighorn sheep herd. Within this area,
about 1,253 acres (42%) is suitable domestic sheep grazing range. Under Alternative 3,
there would be about 3,791 acres of overlap in the allotment with mapped summer range
for S71. Within this area, about 1,293 acres are considered suitable domestic sheep
grazing range, of which 1,122 acres are on NFS lands and 171 acres are on BLM lands.
Under Alternative 3, allotment boundary adjustments would be done specifically to
reduce the total amount of overlap between active and vacant allotments and mapped
summer range for the S71 bighorn sheep herd in the Silverton Landscape. This would be
accomplished, in part, by closing the vacant Little Molas/West Needles Allotment. This
adjustment of the boundary between the active Engine Creek/Deer Creek Allotment and
vacant Little Molas/West Needles Allotment would result in a 21% increase in the area of
overlap in the Engine Creek/Deer Creek Allotment under Alternative 3 (3,791 acres)
compared to Alternative 2 (2,978 acres). The boundary adjustment would also include the
presence of overlap on BLM lands under Alternative 3 that was not present under
Alternative 2. This boundary adjustment however, would provide a more functional
D-11

Silverton Grazing Risk Assessment
allotment configuration for the livestock permittee in the active Engine Creek/Deer Creek
Allotment.
The benefit to bighorn sheep of the boundary adjustment proposed under Alternative 3 is
that under Alternative 3 all of the currently vacant Little Molas/West Needles Allotment
east of U.S. Highway 550, with the exception of a small “doughnut hole” around the Lime
Creek corrals, would be closed, eliminating about 19,891 acres of mapped overlap with
S71 summer range. Under Alternative 2, the entire 20,705 acre Little Molas/West Needles
Allotment would remain vacant and therefore available for stocking administratively at
any time. Because of the boundary adjustment proposed under Alternative 3, there would
be a modest increase (813 acres) in overlap with S71 for the Engine Creek/Deer Creek
Allotment between Alternative 2 and Alternative 3. This increase would be due to some
areas of the vacant Little Molas/West Needles Allotment being added into the active
Engine Creek/Deer Creek Allotment.
The areas of mapped overlap in the Engine Creek/Deer Creek Allotment are in two
discrete areas. The first area is a small “doughnut hole” around the Lime Creek corrals.
The Lime Creek corrals provide one of the few places along U.S. Highway 550 in the
Engine Creek/Deer Creek Allotment where livestock can be loaded or unloaded from
trucks. For this reason, the corrals provide a very important function for the permittee of
the Engine Creek/Deer Creek Allotment. Under Alternative 2, domestic sheep are
unloaded at these corrals, trailed rapidly uphill to the primary forage areas to the west,
then collected at the end of the grazing season and rapidly trailed back down to the
corrals for removal from the allotment. The area is used for one day each going into the
allotment and leaving the allotment. Under Alternative 3 the Lime Creek corrals would be
used for bringing sheep into the allotment, but sheep would then be moved across the
new allotment configuration to the east and picked up in the Molas Pass area at the end
of the grazing season. Ideally, the allotment would then be used in the opposite rotation
the following year. The result of this grazing pattern is that under Alternative 2, domestic
sheep are passing through a small area of mapped S71 summer range near the Lime
Creek corrals for one day, twice each grazing season; one day each on allotment entry and
exit. Under Alternative 3, each season sheep would pass through the S71 summer range
once at the Lime Creek corrals and once in the Molas Pass area.
The Lime Creek corrals sit 0.6 miles below Highway 550, and about 0.8 miles inside the
mapped boundary of S71 summer range. For the first time, during summer 2009, several
small groups of bighorn sheep were observed along the shoulder of Highway 550 about 1
mile west of the corrals. This section of highway is closely surrounded on both sides by a
broad band of dense mature spruce-fir forest on steep north facing slopes. The forest is
consistent with the description provided by Schommer and Woolever (2001) of a
continuous forest that could serve as a natural barrier to bighorn sheep movement. The
area has few rock outcrops or other structures that provide typical bighorn sheep escape
cover. This area is slightly outside the boundary of S71 mapped summer range and just
outside the boundary of the Engine Creek/Deer Creek Allotment as it would be modified
under Alternative 3. The area is within the allotment under the Alternative 2 boundary
configuration. Regardless of allotment boundary configuration, the location of these
sightings was about 1 mile south of the route typically used by domestic sheep to access
the allotment. The domestic sheep permittee has not reported any bighorn sheep
sightings within the portion of the allotment traditionally used by domestic sheep and
none have been reported to the CDOW.
D-12

Silverton Grazing Risk Assessment
The second area of overlap in the Engine Creek/Deer Creek Allotment with S71 summer
range is a linear area that parallels U.S. Highway 550 to the west of the highway near
Molas Pass in an area burned by the Lime Creek fire in the late 1800’s. This area is
mostly gently rolling benches across non-forested areas with few rock outcrops or other
structures that provide typical bighorn sheep escape cover. It is a popular recreation area
and in close visibility from a heavily traveled highway. There have been no sightings of
bighorn sheep in this area. It is about 2 air miles from the rim of the Animas River canyon
across a mixture of dense mature spruce-fir forest and subalpine meadows.
Summary of Risk Rating for Engine Creek/Deer Creek Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Moderate
Under Alternative 2, the presence of the Lime Creek corrals and the need to trail domestic
sheep through mapped bighorn sheep summer range, followed by the close proximity
(about 1 mile) of domestic sheep and 2009 bighorn sheep sightings near the Lime Creek
corrals, combine to result in a rating of “High Risk” for contact. Under Alternative 2 the
Lime Creek corrals are accessed twice per season by the domestic sheep band, increasing
the potential for contact with bighorn sheep, compared to Alternative 3. Domestic sheep
herding techniques however typically bring the sheep rapidly past where the 2009
bighorn sightings occurred and through the zone of overlap with the S71 summer range,
providing some mitigation of the “High Risk” rating.
Under Alternative 3, the application of project design criteria, use of the Lime Creek
corrals only once per season, and modification of the boundary of the Engine Creek/Deer
Creek Allotment shifting domestic sheep presence to areas of overlap that have lower
habitat value for bighorn sheep, combine to result in a rating of “Moderate Risk” for
contact.
Little Molas/West Needles Allotment (FS, vacant allotment):
Under current management, there is about 20,705 acres of overlap in the allotment with
mapped summer range of the S71 West Needles bighorn sheep herd. Within this area,
about 7,556 acres (36%) is suitable domestic sheep grazing range. Of the suitable grazing
range, about 6,434 acres are on NFS lands and 1,122 acres are on BLM lands. Under
Alternative 3, about 19,891 acres of overlap area would be closed to grazing. The
remaining 813 acres of overlap with S71 summer range would be added into the active
Engine Creek/Deer Creek Allotment under a boundary adjustment designed to allow
closure of the remainder of the Little Molas/West Needles Allotment.
The southern portion of this allotment overlaps with substantial areas of mapped bighorn
sheep summer concentration areas on the north end of the West Needle Mountains, and
most of the remainder of the allotment overlaps with mapped summer range. The mapped
summer concentration area is used throughout the summer season by bighorn sheep, as
are portions of the mapped summer range in central portions of the allotment. Under
Alternative 2, the Little Molas/West Needles Allotment east of U.S. Highway 550 would
remain vacant and therefore available for restocking administratively at any time. Much of
the areas of mapped overlap also provide substantial areas of suitable domestic sheep
grazing opportunities, although the allotment has been vacant since 1999.
Under Alternative 3 the Little Molas/West Needles Allotment would be closed to domestic
sheep grazing. However, under Alternative 3, the boundary of the allotment would be
D-13

Silverton Grazing Risk Assessment
adjusted, shifting a small area of the northwest portion of the allotment, north and west
of U.S. Highway 550, into the adjacent active Engine Creek/Deer Creek Allotment. This
would provide a more functional allotment configuration for the permittee of the Engine
Creek/Deer Creek Allotment and facilitate closing the remainder of the Little Molas/West
Needles Allotment.
Closing the Little Molas/West Needles Allotment under Alternative 3 would remove about
19,891 acres of mapped overlap with the S71 West Needles Herd summer range, of which
about 7,515 acres is suitable domestic sheep range. This would close nearly all of the
current allotment east of Highway 550.
Summary of Risk Rating for Little Molas/West Needles Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Low - Closed
Under Alternative 2, if the Little Molas/West Needles Allotment were to be restocked, the
substantial area of overlap between known bighorn sheep use areas and suitable
domestic sheep grazing areas results in a rating of “High Risk” for contact throughout the
majority of the allotment. If however, the allotment were to remain vacant under
Alternative 2, the risk rating would be “Low” because domestic sheep would not be
permitted in the allotment and there would be a “Low Risk” for contact. However, because
the allotment could be restocked administratively at any time, the overall rating of this
allotment under Alternative 2 would be “High Risk”.
Under Alternative 3, the Little Molas/West Needles Allotment would be closed to domestic
sheep grazing. The rating would be “Low Risk” because domestic sheep would not be
permitted in the allotment and there would be a low risk for contact.
Needles Mountains Allotment (FS, vacant allotment):
Under current management, there is about 11,898 acres of overlap in the allotment with
mapped summer range of the S71 West Needles bighorn sheep herd. Within this area,
only about 615 acres (5%) is suitable domestic sheep grazing range. Very little suitable
domestic sheep range exists in the allotment due to generally steep and rugged
mountainous terrain. Under Alternative 3, the preferred alternative, the entire allotment
would be closed to grazing.
There is a large area of overlap with mapped summer range, summer concentration, and
winter range areas with the S71 West Needles bighorn sheep herd. The mapped summer
concentration area is used throughout the summer season by bighorn sheep. Much of the
area of mapped overlap is steep, rocky terrain providing few opportunities for suitable
domestic sheep grazing, but good escape cover and foraging areas for bighorn sheep.
There are no records of any permitted livestock being grazed on this allotment.
D-14

Silverton Grazing Risk Assessment
Summary of Risk Rating for Needles Mountains Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Low - Closed
Under Alternative 2, if the Needles Mountains Allotment were to be stocked, the
substantial area of overlap between known bighorn sheep use areas and suitable
domestic sheep grazing areas results in a rating of “High Risk” for contact. If however, the
allotment were to remain vacant under Alternative 2, the rating would be “Low Risk”
because domestic sheep would not be permitted in the allotment and there would be a low
risk for contact. However, because the allotment could be restocked administratively at
any time, the overall rating of this allotment under Alternative 2 would be “High Risk”.
Under Alternative 3, the Needles Mountains Allotment would be closed to domestic sheep
grazing. The rating would be “Low Risk” because domestic sheep would not be permitted
in the allotment and there would be a low risk for contact.
Flume Allotment (FS, vacant allotment):
Under current management, there is about 653 acres of overlap in the allotment with
mapped summer range for the S71 West Needles bighorn sheep herd. Within this area,
only about 29 acres (4%) is suitable domestic sheep grazing range. The area of mapped
overlap is heavily forested with dense mature forest with few rock outcrops and provides
little suitable habitat for bighorn sheep, and little suitable forage for domestic sheep. For
these reasons, domestic sheep would pass rapidly from their drop off point through the
narrow zone of overlap to the nearest grazing areas to the north of the zone of overlap.
The habitats in this portion of the allotment are consistent with the description provided
by Schommer and Woolever (2001) of a continuous forest that could serve as a natural
barrier to bighorn sheep movement. The area has few rock outcrops or other structures
that provide typical bighorn sheep escape cover. It is about 3.5 air miles from the rim of
the Animas River canyon to the nearest suitable domestic sheep grazing area. There have
been no recent Bighorn sheep sightings in the mapped overlap area. This allotment has
been vacant since 1989.
This allotment is proposed to be placed into forage reserve status. When active however,
all of the project design criteria and adaptive management practices for active allotments
would be applied to this allotment. We anticipate this allotment may be used once per 15
years in an emergency situation, such as the Missionary Ridge fire of 2002.
Summary of Risk Rating for Flume Allotment:
Risk Rating: Alternative 2 – Low
Alternative 3 – Low
Under Alternative 2, if the Flume Allotment were to be restocked, the lack of suitable
habitat for domestic sheep or bighorn sheep in or near the zone of overlap, and the
distance from the Animas River canyon (about 3.5 miles) results in a rating of “Low Risk”
for contact. If the allotment were to remain vacant under Alternative 2, the rating would
be “Low Risk” because domestic sheep would not be permitted in the allotment and there
would be a low risk for contact.
Under Alternative 3, the Flume Allotment would be managed as a forage reserve allotment
and grazed by domestic sheep only on an irregular basis. Project design criteria would be
applied to the allotment when it was active, and the habitat conditions described above
would all result in a rating of “Low Risk” for contact.
D-15

Silverton Grazing Risk Assessment
Minnie Gulch Allotment (BLM, vacant allotment):
Under current management, there is about 2,536 acres of overlap in the allotment with
mapped summer range for the S33 Pole Mountain/Upper Lake Fork bighorn sheep herd.
Within this area, only about 319 acres (13%) is suitable domestic sheep grazing range.
Under Alternative 3, the preferred alternative, the entire allotment would be closed to
grazing. The Minnie Gulch Allotment has been vacant since 1983.
Surveys conducted in the allotment by BLM staff over the past 4 summer seasons have
failed to detect bighorn sheep, but CDOW continues to receive regular reports of sheep in
the gulch during summer. It is thought likely that bighorn sheep reported in the gulch
may be coming from nearby Crown Mountain or the Pole Creek Mountain subpopulation
on the Rio Grande National Forest.
Much of this allotment is open alpine terrain providing a good mix of bighorn forage areas
and escape cover. It also provides areas of domestic sheep grazing opportunities. Bighorn
are known to use the adjacent Cottonwood Allotment (Gunnison NF) and the habitats in
Minnie Gulch Allotment provide a natural extension for bighorn sheep using the
headwaters of Cuba Gulch. Given the close proximity of Minnie Gulch to areas known to
be regularly used by bighorn sheep, the topography of the allotment that acts as a natural
extension for bighorns using the headwaters of Cuba Gulch, and regular reports of
bighorn sheep in Minnie Gulch, there appears to be a high risk for contact between
domestic and bighorn sheep in this allotment.
Summary of Risk Rating for Minnie Gulch Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Low - Closed
Under Alternative 2, if the Minnie Gulch Allotment were to be restocked, the substantial
area of overlap between suitable domestic sheep grazing areas and mapped bighorn
summer range, the close proximity of the allotment to known bighorn use areas, the
potential expansion of the S33 bighorn herd, and the regularity of reports of bighorn in
the allotment, these factors in combination result in a rating of “High Risk” for contact. If
however, the allotment were to remain vacant under Alternative 2, the rating would be
“Low Risk” because domestic sheep would not be permitted in the allotment and there
would be a low risk for contact. However, because the allotment could be restocked
administratively at any time, the overall rating of this allotment under Alternative 2 would
be “High Risk”.
Under Alternative 3, the Minnie Gulch Allotment would be closed to domestic sheep
grazing. The rating would be “Low Risk” because domestic sheep would not be permitted
in the allotment and there would be a low risk for contact.
Gladstone Allotment (BLM, active allotment):
In the active BLM Gladstone Allotment there is a small area in the southern end of the
allotment that overlaps with mapped summer range for the S71 West Needles bighorn
sheep herd. Under current management, there is about 320 acres of overlap, with only
about 11 acres (3%) being suitable domestic sheep grazing range.
Surveys conducted in the allotment by BLM staff in summer 2008 failed to detect bighorn
sheep. The area of mapped overlap is immediately adjacent to the town of Silverton, on
the north side of town. Bighorns would have to pass through town or around town
D-16

Silverton Grazing Risk Assessment
through heavily forested steep north facing hillsides to access this area. The area
bighorns would have to pass through, and much of the area of overlap itself, is consistent
with the description provided by Schommer and Woolever (2001) of a continuous forest
that could serve as a natural barrier to bighorn sheep movement. The area of overlap does
have some rock outcrops and talus slopes that provide typical bighorn sheep escape
cover. There have been no sightings of bighorn sheep in the area, and it is about 4.5 miles
down the Animas River canyon to areas known to be used by bighorn sheep.
Under current management, the domestic sheep permittee does not use the southern
portion of the Gladstone Allotment, including all of the area of mapped overlap. Under
Alternative 3, domestic sheep would not be permitted to graze in the Cement Creek
drainage south of Hancock Gulch on either side of Cement Creek. Hancock Gulch is
about 1.0 mile north of the boundary of the summer range area for S71. In the adjacent
Forest Service Red Mountain Allotment, domestic sheep are not permitted to graze south
of Ohio Peak, about 2.5 miles to the north and west of mapped bighorn summer range.
Summary of Risk Rating for Gladstone Allotment:
Risk Rating: Alternative 2 – Low
Alternative 3 – Low
Under Alternative 2, the permittee does not use the extreme south end of the Gladstone
Allotment where the zone of overlap occurs due to dense forest cover and lack of suitable
domestic sheep forage. The lack of suitable forage areas for bighorn sheep in the zone of
overlap, the distance from bighorn use areas in the Animas River canyon (about 4.5
miles), and the town of Silverton acting as a barrier to bighorn movement together result
in a rating of “Low Risk” for contact.
Under Alternative 3, the Gladstone Allotment would be closed to grazing south of Hancock
Gulch and the adjacent Red Mountain Allotment would be closed to grazing south of Ohio
Peak. Project design criteria would be applied to sheep grazing the remainder of the
Gladstone allotment, and the habitat conditions described above in the area of mapped
overlap, would together result in a rating of “Low Risk” for contact.
Picayne/Mineral Point Allotment (BLM, active allotment):
Under current management, there is about 2,158 acres of overlap in this active BLM
allotment with mapped summer range for the S33 Pole Mountain/Upper Lake Fork
bighorn sheep herd. Within this area, about 378 acres (18%) is suitable domestic sheep
grazing range.
BLM grazing records for this allotment date back to 1967 but domestic sheep have been
grazed here since prior to the Second World War. Prior to 1990, the stocking rate of this
allotment was about twice what it is currently. Most of the south half of the allotment
provides suitable domestic sheep grazing and there is good access to most of the
allotment by 4WD roads.
The area of overlap with bighorn summer range covers nearly the entire southern half of
the allotment south of the ghost town of Animas Forks. Although much of the allotment is
steep, there is little rocky terrain or talus slopes for bighorn escape cover west of the
Animas River canyon. Most of the terrain in the south half of the allotment is alpine
meadows bisected by high ridges and steep slopes and canyons traversing higher alpine
peaks.
D-17

Silverton Grazing Risk Assessment
There is evidence that the S33 Pole Mountain/Upper Lake Fork Herd experienced a
significant and widespread die-off in the late 1980’s. However, there is no evidence
suggesting contact with domestic sheep in the Picayne/Mineral Point Allotment was
related to the incident. There has been no indication that domestic sheep grazing in this
allotment have contacted bighorn sheep or been related to disease events in the S33
bighorn herd.
Under Alternative 2, the permittee has the option of accessing the south half of the
allotment by trailing from Engineer Pass south and west around the Animas Forks
townsite, then tailing down the Animas River road (State Highway 110) to Picayne Gulch,
then up the road (County Road 9) to the head of Picayne Gulch. Or, the permittee could
access the same area by trailing around the west side of the Animas Forks townsite, then
trailing up steep avalanche chutes to the basins east and south of Treasure Mountain.
Under Alternative 3, the permittee would trail around the west side of the Animas Forks
townsite, then trail up the steep avalanche chutes to the alpine the basins east and south
of Treasure Mountain.
Surveys for bighorn were conducted by BLM employees in the area of overlap over the
past four summer seasons and no bighorn sheep have been detected in the allotment. The
domestic sheep permittee has reported no sightings of bighorn sheep in the allotment.
The allotment is also heavily used by the public for motorized recreation with an extensive
network of heavily traveled 4x4 roads and no bighorn sheep have been reported to CDOW
in the area of overlap.
BLM staff surveys have detected bighorn sheep in four of the last five summer seasons in
Grouse Gulch and Burns Gulch, two side canyons directly across the Animas River from
the allotment on the east side of the Animas River canyon. Bighorn sheep have been
detected each summer in Grouse Gulch, only about 0.25 miles east of the Animas River
road, near the mouth of the gulch. The Animas River road has been used for decades by
the Picayne/Mineral Point Allotment permittee as a trailing route to access the south half
of the allotment. This trailing route would continue to be permitted under Alternative 2.
The trailing route most likely used by the permittee under Alternative 3 would be about 1
air mile west of the Grouse Gulch bighorn use area and on the west side of the Animas
River canyon. Portions of Burns Gulch where bighorn sheep have been detected are about
1 air mile east of the allotment’s active grazing areas, but across the Animas River
canyon. Crown Mountain and Niagara Peak are about 2.0 air miles east of the allotment
and are believed to be summering areas regularly used by bighorn sheep.
Summary of Risk Rating for Picayne/Mineral Point Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Moderate
Under Alternative 2, the close proximity of domestic sheep to known bighorn use areas
(about 1 mile), very close proximity of a domestic sheep driveway to bighorn use areas
(about 0.25 mile), and proximity of grazed portions of the allotment to bighorn use areas
(about 2 miles), and the potentially expanding nature of the S33 bighorn sheep herd,
together result in a rating of “High Risk” for contact throughout the south half of the
Picayne/Mineral Point Allotment.
Under Alternative 3, the application of additional herding techniques and project design
criteria described below (Table 3), the use of a more westerly driveway to access the south
half of the allotment, the lack of bighorn occurrences in the allotment, the lack of bighorn
D-18

Silverton Grazing Risk Assessment
preferred habitat components in the allotment, and decades of historic use of the
allotment without evidence of contact with bighorns from S33, in combination result in a
rating of “Moderate Risk” for contact in the Picayne/Mineral Point Allotment.
Eureka Allotment (BLM, active allotment):
Under current management, there is only about 183 acres of overlap in the active BLM
Eureka Allotment with mapped summer range for the S33 Pole Mountain/Upper Lake
Fork bighorn sheep herd. Within this area, only about 43 acres (23%) is suitable domestic
sheep grazing range. The overlap area is a small narrow area on the east side of the
allotment.
Domestic sheep have been grazed here since prior to the Second World War. Prior to
1992, the stocking rate of this allotment was about twice what it is currently. The
permittee accesses the allotment by trucking sheep to a set of corrals just south of the
town site of Eureka, then trailing sheep into Eureka Gulch along the road.
The area of overlap with bighorn summer range is a relatively small area in the east
central part of the allotment along the north side of Eureka Gulch. Although the overlap
area is steep alpine slopes, there is little rocky terrain or talus slopes for bighorn escape
cover. Most of the terrain in the allotment is alpine meadows bisected by high ridges and
steep slopes and canyons traversing higher alpine peaks, with some patches of mature
spruce-fir forest along the South Fork Animas River canyon. Elevations in the allotment
vary from 9,800 feet to just over 13,400 feet. The allotment includes the headwaters of the
West Fork and the South Fork of the Animas River. There is good access to most of the
allotment by 4WD roads.
Elevations on the allotment vary from 9,800 feet to just over 13,400 feet. The terrain
consists of high ridges and steep slopes with canyons throughout the rugged mountains.
The allotment occurs at the headwaters of the West Fork and the South Fork of the
Animas River. There is good access to most of the allotment by 4WD roads.
The area of mapped overlap with bighorn sheep summer range in the Eureka Allotment is
generally not used by the permittee. Domestic sheep are generally grazed west of the area
of mapped overlap. The area of overlap is on the north wall of Eureka Gulch and about
1.0 mile west of the Animas River. Portions of Burns Gulch where bighorn sheep have
been detected are about 2.0 air miles northeast of the mapped overlap area. Crown
Mountain and Niagara Peak are about 3.0 air miles east of the allotment and are believed
to be summering areas regularly used by bighorn sheep. The Eureka corrals are about 1.5
air miles west of Crown Mountain, and about 0.25 mile south of and outside the S33
summer range boundary. The north half of the allotment shares its east boundary with
the Picayne/Mineral Point Allotment and the western most boundary of S33 summer
range.
Surveys for bighorn sheep were conducted by BLM employees over the past four summer
seasons, including in the area of mapped overlap, and no bighorn sheep were detected in
the allotment or near the Eureka corrals. The domestic sheep permittee has reported no
sightings of bighorn sheep in the allotment. The allotment is also heavily used by the
public for motorized recreation with an extensive network of heavily traveled 4x4 roads
and no bighorn sheep have been reported to CDOW in the area of overlap.
Summary of Risk Rating for Eureka Allotment:
Risk Rating: Alternative 2 – High
D-19

Silverton Grazing Risk Assessment
Alternative 3 – Moderate
Under Alternative 2, the close proximity of the Eureka corrals and sheep driveway to
bighorn use areas (about 1.5 miles), the proximity of the mapped overlap area to known
bighorn use areas (about 2.0 miles), the close proximity of the north half of the allotment
to mapped bighorn summer range (sharing a common boundary for several miles), and
the expanding nature of the S33 bighorn sheep herd, together result in a rating of “High
Risk” for contact in the Eureka Allotment.
Under Alternative 3, the application of additional herding techniques and project design
criteria described below (Table 3), the lack of domestic sheep use of the area of overlap,
the lack of bighorn occurrences in the allotment or west of the Animas River, the lack of
bighorn preferred habitat components in the allotment, and decades of historic use of the
allotment without evidence of contact with bighorns from S33, together result in a rating
of “Moderate Risk” for contact in the Eureka Allotment.
Maggie Gulch Allotment (BLM, active allotment):
In the active BLM Maggie Gulch Allotment there is no overlap with mapped bighorn sheep
summer range. However, much of the northeast boundary of the allotment adjoins the
southern boundary of mapped summer range for the S33 Pole Mountain/Upper Lake
Fork bighorn sheep herd. This shared common boundary runs along the crest of a
ridgeline that separates Maggie Gulch from Minnie Gulch to the north. The Colorado
Division of Wildlife has received occasional reports of bighorn sheep along the crest of this
ridge. The upper half of Maggie Gulch is where most of the domestic sheep grazing occurs
in this allotment. Most of the allotment is relatively broad rolling alpine plateaus and
basins with relatively little rocky terrain or talus slopes for bighorn escape cover.
Surveys for bighorn sheep were conducted by BLM employees in summer 2008 and no
bighorn sheep were detected in the allotment. The domestic sheep permittee has reported
no sightings of bighorn sheep in the allotment. Maggie Gulch is a popular area for
summer recreation with good road access but no bighorn sheep have been reported to
CDOW.
Domestic sheep have been grazed in the Maggie Gulch Allotment since prior to the Second
World War. Stocking records since 1953 indicate similar numbers of sheep were grazed
throughout this period to what is currently permitted.
Summary of Risk Rating for Maggie Gulch Allotment:
Risk Rating: Alternative 2 – Moderate
Alternative 3 – Moderate
Under Alternative 2, the close proximity of the north half of the allotment to mapped
bighorn summer range (sharing a common boundary for several miles), and the
expanding nature of the S33 bighorn sheep herd, together result in a rating of “Moderate
Risk” for contact in the Maggie Gulch Allotment.
Under Alternative 3, the application of additional herding techniques and project design
criteria described below (Table 3), the lack of bighorn occurrences in the allotment, the
lack of bighorn preferred habitat components in grazed portions of allotment, and decades
of historic use of the allotment without evidence of contact with bighorns from S33,
together result in a rating of “Moderate Risk” for contact in the Maggie Gulch Allotment.
D-20

Silverton Grazing Risk Assessment
West Lime Allotment (FS, vacant allotment):
In the vacant FS West Lime Allotment there is no overlap with mapped bighorn sheep
summer range. However, for the past several summers Colorado Division of Wildlife has
received regular reports of small numbers of bighorn sheep summering in Ice Lakes Basin
near the headwaters of South Mineral Creek. It is not known with certainty which bighorn
herd these individuals are likely to be coming from, or how far and from where they are
travelling to reach this area. There is no evidence to indicate these animals are wintering
in the basin. The allotment has been grazed since at least the 1950’s, with stocking rates
that are about 3 times the currently permitted numbers. The allotment has been vacant
since 1999.
Much of the allotment is heavily forested with dense extensive areas of mature spruce-fir
forest. The allotment also contains a substantial amount of rocky and rugged
mountainous terrain with elevations that vary from about 9,000 feet to well over 13,000
feet. Much of the alpine zone of this allotment is steep, rugged mountain peaks with deep
canyons, waterfalls, cliffs, and many rocky areas and talus slopes providing good bighorn
escape cover. The allotment is a popular summer recreation area, especially in the South
Mineral Creek drainage and along the Colorado Trail corridor.
Summary of Risk Rating for West Lime Allotment:
Risk Rating: Alternative 2 – High
Alternative 3 – Low - Closed
Under Alternative 2, if the West Lime Allotment were to be restocked, the presence of
bighorn sheep summering in the Ice Lakes Basin area would result in a rating of “High
Risk” for contact. The Ice Lakes Basin area would be needed to provide an effective
allotment configuration and prevent new resource damage associated with domestic
sheep grazing activities. If however, the allotment were to remain vacant under Alternative
2, the rating would be “Low Risk” because domestic sheep would not be permitted in the
allotment and there would be a low risk for contact. However, because the allotment could
be restocked administratively at any time, the overall rating of this allotment under
Alternative 2 would be “High Risk”.
Under Alternative 3, the West Lime Allotment would be closed to domestic sheep grazing.
The rating would be “Low Risk” because domestic sheep would not be permitted in the
allotment and there would be a low risk for contact.
D-21

Silverton Grazing Risk Assessment
Remaining Allotments (BLM and FS):
The 5 remaining allotments in the Silverton Landscape are Red Mountain (FS - active),
Elk Creek (FS and BLM - active), Deer Park (FS and BLM - active), Graysill (FS - vacant),
and Silverton Watershed (FS - closed). There is no overlap in any of these allotments with
mapped bighorn sheep summer range. All allotments are well removed from mapped
bighorn sheep summer range. For these reasons, the rating would be “Low Risk” for
contact between domestic sheep and bighorn sheep in Red Mountain, Elk Creek, Deer
Park, Graysill, and Silverton Watershed allotments.
RESULTS
Risk Rating: Alternative 2 – Low
Alternative 3 – Low
Of the 15 allotments analyzed in the Silverton Landscape EA (see Table 2, below), 8
overlap with mapped bighorn sheep summer range (see Figures 1 and 2, below). Under
Alternative 2, current management, 6 of these 8 allotments were rated as having “High
Risk” for contact with bighorn sheep, including the vacant allotments if they were
restocked (see Figure 3, below). The remaining two allotments with overlap were rated as
“Low Risk” due to site specific factors (see Figure 3, below).
Under Alternative 3, the three active allotments having overlap with bighorn sheep
summer range would all receive a rating of “Moderate Risk” (see Figure 4, below). These
allotments are: Engine Creek/Deer Creek (FS), Eureka/California Gulch (BLM), and
Picayne/Mineral Point (BLM). The two allotments with a “Low Risk” rating under
Alternative 2 would remain “Low Risk” under Alternative 3 These allotments are:
Gladstone (BLM), and Flume (FS). The three allotments with a “High Risk” rating under
Alternative 2 that would be closed under Alternative 3 would receive a rating of “Low Risk”
under Alternative 3. These allotments are: Little Molas/West Needles (FS), Minnie Gulch
(BLM), and Needles Mountains (FS).
Of the 7 remaining allotments that do not overlap with mapped bighorn summer range, 5
are rated as “Low Risk” for contact under both Alternative 2 and Alternative 3 (see Figures
3 and 4, below). These allotments are: Red Mountain (FS), Elk Creek (FS/BLM), Deer Park
(FS/BLM), Graysill (FS), and Silverton Watershed (FS). Of the final two allotments, one
allotment is rated as “Moderate Risk” for contact with bighorn sheep under both
Alternative 2 and Alternative 3 (Maggie Gulch, BLM), and the second is rated as “High
Risk” under Alternative 2 and “Low Risk” under Alternative 3 (West Lime, FS).
Under Alternative 2, current management, there is a total of about 41,430 acres of
overlap between active and vacant domestic sheep grazing allotments and mapped
bighorn sheep summer range in the Silverton Landscape. Of these overlap areas, about
5,639 acres are in active allotments, and 35,792 acres are in currently vacant allotments
(see Figure 1, below). Under Alternative 2, about 40,430 acres of overlap would occur in
allotments rated as “High Risk” for contact between domestic sheep and bighorn sheep
(see Figure 3, below).
Under Alternative 3, only about 7,105 acres of overlap would remain between active and
vacant domestic sheep allotments and bighorn sheep summer range. Within these 7,105
acres of overlap, about 6,132 acres would be rated as “Moderate Risk” for contact, and
973 acres would be rated as “Low Risk” for contact (see Figure 4, below). Under
Alternative 3, no acres of overlap would remain in “High Risk” areas.
D-22

Silverton Grazing Risk Assessment
Under Alternative 3, the preferred alternative, the amount of overlap between active and
vacant domestic sheep allotments and mapped bighorn sheep summer range in the
Silverton Landscape would be reduced by 83%, primarily by closing allotments that have
remained vacant for the past decade or more.
Of the 7,105 acres of overlap under Alternative 3, about 6,452 acres would be in active
allotments and 653 acres would be in a forage reserve allotment. Alternative 3 would
therefore result in an increase of 813 acres over Alternative 2 of overlap between domestic
sheep grazing in active allotments and mapped bighorn summer range, all in the Engine
Creek/Deer Creek Allotment. For the reasons stated above, we believe this increase in
overlap acres under Alternative 3 ultimately benefits bighorn sheep. This is because the
813 additional acres of overlap in this active allotment would be in an area judged to be
“Moderate Risk” for contact. Including these 813 additional acres in a “Moderate Risk”
area would allow the closing of about 19,891 acres in areas rated as “High Risk” under
Alternative 2.
To summarize the results in a different way, under Alternative 2 about 40,458 acres of
overlap would be in areas rated as “High Risk” for contact, there would be 0 acres in
areas rated as “Moderate Risk”, and 973 acres would be in areas rated as “Low Risk”.
Under Alternative 3, there would be 0 acres of overlap in areas rated as “High Risk” for
contact, there would be 6,132 acres in areas rated as “Moderate Risk”, and 35,298 acres
would be in areas rated as “Low Risk”.
The domestic livestock permittees and agency livestock permit administrator meet each
winter to discuss annual operating instructions for the upcoming grazing season. In
conjunction with this meeting, the agency wildlife biologist and CDOW staff will meet with
the permittee to review the effectiveness of project Design Criteria implementation and
any new bighorn sheep information obtained over the previous year. At this time, the risk
assessment rating for each allotment will be reviewed as necessary, and updated with
new information as appropriate. Discussion with permittees about management actions,
observations, and opinions are a critical component for finding consensus based solution
opportunities to new issues as they arise. These meetings will include staff from adjacent
land management administrative units, as necessary, to facilitate discussions of
opportunities for utilizing grazing options on adjacent units. The objective of these
discussions would be to explore mutually acceptable ways to reduce the risk of contact
between bighorn sheep and domestic sheep using a flexible adaptive approach to problem
solving, and to be more responsive to the management needs of livestock permittees and
the dynamic nature of a highly mobile wildlife species.
Annual reviews of risk assessment ratings and the potential for contact between domestic
and bighorn sheep may be necessary because the S33 Pole Mountain/Upper Lake Fork
bighorn sheep herd appears to be increasing in numbers and possibly expanding in
range. For this reason, the extent of occupied summer range may vary from one season to
the next, necessitating an adaptive approach to where and how domestic sheep are
managed on the landscape.
Wildlife staff of the FS/BLM will work with the local staff of the Colorado Division of
Wildlife to develop and implement a coordinated annual monitoring plan for bighorn
sheep in the upper Animas River basin. Given the designation by CDOW of the S33
bighorn herd as a primary (“Tier 1”) population ranked as a high priority for conservation
at a statewide level, it is logical for CDOW and BLM to place a greater emphasis on
D-23

Silverton Grazing Risk Assessment
monitoring the occurrence, distribution, and use patterns of bighorn sheep in BLM
portions of the Silverton Landscape. Monitoring information would then be used to inform
and revise the Risk Assessment process for the affected allotments. Annual monitoring
activities could include coordinated ground counts, expanded aerial counts, radio/GPS
collars, etc. A key component of the monitoring plan should be to implement a system for
immediate cross-agency sharing of bighorn sighting reports and monitoring information
to keep all parties informed about bighorn use of the upper Animas River Basin.
Table 2. Risk rating of allotments under Alternative 2 (current management) and
under Alternative 3 (the preferred alternative) in the Silverton Landscape grazing
analysis area.
Allotment (Agency)
Red Mountain (FS)
Elk Creek (FS/BLM)
Deer Park (FS/BLM)
Engine Creek/Deer Creek (FS)
Gladstone (BLM)
Eureka/California Gulch (BLM)
Picayne/Mineral Point (BLM)
Maggie Gulch (BLM)
Overlap with
Bighorn Herd
Allotment Risk under Risk under
Status Alternative 2 Alternative 3
Active Low Low
Active Low Low
Active Low Low
S71 Active High Moderate
S71 Active Low Low
S33 Active High Moderate
S33 Active High Moderate
Active Moderate Moderate
West Lime (FS) Vacant High Low - Closed
Little Molas/West Needles (FS) S71 Vacant High Low - Closed
Minnie Gulch (BLM) S33 Vacant High Low - Closed
Needles Mountains (FS) S71 Vacant High Low - Closed
Graysill (FS) Vacant Low Low
Flume (FS) S71 Vacant Low Low – Forage
Reserve
Silverton Watershed (FS) Closed Low Low
D-24

Silverton Grazing Risk Assessment
LITERATURE CITED
Aune, K., N. Anderson, D. Worley, L. Stackhouse, J. Henderson, and J. Daniel. 1998. A
comparison of population and health histories among seven Montana bighorn
sheep populations. Biennial Symposium of the Northern Wild Sheep and goat
Council. 11:46-69.
Beecham, J. J., C. P. Collins, and T. D. Reynolds 2007. Rocky Mountain bighorn sheep
(ovis canadensis): a technical conservation assessment. [Online]. USDA Forest
Service, Rocky Mountain Region. Available on the internet at:
http://www.fs.fed.us/r2/projects/scp/assessments/rockymountainbighornsheep.p
df.
Colorado Division of Wildlife. 2009. memorandum of understanding for management of
domestic sheep and bighorn sheep. February 11, 2009.
Diamond, B. 2005. Abbreviated summary for Unit S-33, the Pole Mountain/Upper Lake
Fork bighorn sheep herd. Unpublished report, Colorado Division of Wildlife, Fort
Collins, CO. 6 pp.
George, J. L., R. Kahn, M. W. Miller, and B. Watkins. 2008. Colorado bighorn sheep
management plan 2008 – 2018. Colorado Division of Wildlife, 6060 Broadway,
Denver, CO, 80216. 96 pp.
Martin, K. D., T. J. Schommer, and V. L. Coggins. 1996. Literature review regarding the
compatibility between bighorn and domestic sheep. Proceedings of the Tenth
Biennial Symposium of the Northern Wild Sheep and Goat Council 10:72-77.
Onderka, D. K., and W. D. Wishart. 1984. A major bighorn sheep die-off from pneumonia
in southern Alberta. Proceedings of the Fourth Biennial Symposium of the
Northern Wild Sheep and Goat Council 4:356-363.
Schommer, T., and M. Woolever. 2001. A process for finding management solutions to the
incompatibility between domestic and bighorn sheep. USDA Forest Service,
Washington, DC. 62 pp.
USDI Bureau of Land Management. 1998. Instruction memorandum 98-140. Revised
guidelines for management of domestic sheep and goats in native wild sheep
habitats. USDI-BLM, Washington, DC. 6 pp.
Western Association of Fish and Wildlife Agencies. 2007. Recommendations for domestic
sheep and goat management in wild sheep habitat. Wild Sheep Working Group,
Initial Subcommittee, K. Hurley, Chair, June 21, 2007. Available on the internet at:
http://www.mwvcrc.org/bighorn/wafwawildsheepreport.pdf.
D-25

Silverton Grazing Risk Assessment
Table 3. Project Design Criteria to minimize contact between Bighorn and
Domestic Sheep.
High Risk Allotments:
Alternative
Risk Assessments (in the project record) 2 3
Permitted domestic sheep and goat grazing will not be authorized within high risk areas of the allotment.
In most instances, domestic sheep may still be authorized within the allotment but management will
ensure routing and other design criteria to avoid the high risk areas. This can be accomplished through
adaptive management tools.
Moderate Risk Allotments:
Permitted domestic sheep and goat grazing may be authorized. However, design criteria will still be
implemented to strive to reduce the potential for contact even farther.
Low Risk Allotments:
Permitted domestic sheep and goat grazing may be authorized. Permitted domestic sheep grazing will
be focused towards these areas. However, design criteria should still be implemented to strive to
reduce the potential for contact even farther.
x
Alternative
Minimization of Threat of Disease Transmission 2 3
Follow the response protocol for confirmed contact or threat of impending contact between permitted
domestic sheep and bighorn:
Permittee:
The permittee or their agent will contact the Columbine Ranger District/Field Office range personnel
immediately if bighorn come into contact or there is a threat of impending contact with domestic sheep.
Contact information as well as phone numbers will be included in the Annual Operating Instructions.
Permittees authorized to graze in areas rated as “Moderate Risk”, will require herders to carry and use a
“SPOT satellite messenger” to allow for the immediate notification and location of domestic sheep and
bighorn contact or impending contact due to unforeseen movements of the domestic sheep and/or
bighorn. Information about the “SPOT” device is available at: http://www.findmespot.com/en/
As an immediate response, the permittee and/or the herders will be authorized to haze bighorn that are
threatening to make contact with domestic sheep. This will be accomplished through an agreement
between the grazing permittee and the CDOW. The agreement will include circumstances requiring
hazing response, appropriate type of hazing and reporting requirements.
Forest Service/BLM:
When informed about potential bighorn/domestic sheep contact, the FS/BLM will contact the permittee
immediately notifying them of the situation. At this point, the FS/BLM and the permittee will implement
other design criteria if needed to prevent or reduce the threat of impending contact. At this time an
alternate plan of grazing for the remainder of the season, “flexible management” may be implemented to
strive to prevent contact from occurring.
Concurrently, as contact or the threat of contact is made known, the FS/BLM will contact the CDOW
(contact information will be provided to the FS and the permittee prior to the grazing season). Actions
that the CDOW will take is at their discretion concerning wildlife health intervention and management of
the bighorn. CDOW will inform the FS/BLM if the situation is rectified and discussion/planning will occur
with the permittee to implement an alternate management strategy if needed. The CDOW may
implement post contact monitoring.
The FS/BLM will make the particular domestic sheep band (and the area) a high priority for monitoring to
determine if there is bighorn activity in the area or if the risk analysis should be revisited.
The FS/BLM will work with CDOW to prioritize and implement coordinated annual monitoring of bighorn
x
D-26

Silverton Grazing Risk Assessment
sheep individuals and populations using the upper Animas River Basin. Monitoring activities could
include coordinated ground counts, aerial counts, radio/GPS collars, etc. Implement a system for
immediate cross-agency sharing of bighorn sighting reports to keep all parties informed about bighorn
use of the upper Animas River Basin.
Annually, in conjunction with CDOW and the permittee, review the effectiveness of Design Criteria
implementation and new information such as recent bighorn sightings. Update the allotment Risk
Assessment if necessary, and make adjustments to upcoming grazing accordingly. These adjustments
may include adjacent BLM and/or USFS administrative units, depending on availability and feasibility.
Feasibility includes the permittees’ needs as well as the administrative availability of allotments on other
administrative units. Adjustments will be focused on reducing the risk of interactions if the risk has
increased to an unacceptable level.
Sheep and goat allotments with mapped overlap of bighorn summer range will be evaluated for closure
when/if permits are relinquished back to the FS/BLM.
Herding:
Alternative
Minimization of Threat of Disease Transmission 2 3
At least one herder is required to be with the sheep. The main flock will never be left unattended, except
at night, and short periods when the herder is accomplishing other tasks in the immediate area. A
herder must remain in the camp during the night.
Trailing of domestics will happen as much during the middle of the day to avoid bighorns as possible. In
certain areas this will not be possible due to conflicts with recreation users.
Sick or diseased domestic sheep and goats – pre turnout:
It is imperative that permittees maintain a high certainty of domestic animal health in their permitted
stock. Permittees/Herders will take appropriate measures to prevent turnout of sick or diseased domestic
sheep and goats on grazing allotments, on trailing routes, or in weed control or pack-stock situations. It
should also be recognized that “healthy-appearing” domestic sheep and goats may still carry pathogens
(harmless to them) that can be transmitted to wild sheep.
Sick or diseased domestic sheep and goats – post turnout:
Injured, sick or diseased livestock will not be left behind but will be removed or terminated and disposed
of according to the “Disposal of Dead Livestock” requirements above and in accordance with State
Statute. Sick or diseased animals will be removed or otherwise eliminated when identified.
Sick or diseased bighorn sheep:
Sick bighorn sheep or carcasses must be reported as soon as possible to the Columbine Ranger
District/Field Office range personnel. Agency personnel will then notify the CDOW as soon as possible.
Salting:
Every effort should be made to deny bighorn access and consequent attraction to the domestic sheep
salting activities. Leaving available salt or excess salt residue in the soil or on rocks or tubs presents a
salt source that may attract bighorn and may even train bighorn to follow the domestic sheep bands in
search of salt.
Blocks of salt will be allowed and, if used, will be kept with the domestic sheep at all times. Salt will not
be left behind when the domestic sheep are moved.
Salt or supplement will be placed only on rocky knolls, well-drained sites or in timber where excessive
trampling will not destroy plant growth. Salt or supplement will not be placed closer than ¼ mile to
streams, springs, water developments, or other wetlands without prior approval of the Agency Officer.
Salt or supplement will not be placed near trailheads, on open roads, in natural travel routes, passes,
parks, meadows, in areas of concentrated public use, or in other areas where such placement is liable to
result in conflicts with other public land users. Salt or supplement will not be placed within tree
regeneration areas where the smallest trees are less than three feet tall.
x
x
x
x
x
x
D-27

Silverton Grazing Risk Assessment
Herder education:
It is of utmost importance that the permittees spend as much time as necessary teaching the herders the
requirements attached to the grazing permit, annual operating instructions and all the applicable Project
Design Criteria included here. With the implementation of “adaptive management,” areas authorized for
grazing as well as routing patterns and schedules may change from year to year and even within the
year, along with other management techniques. Following procedures to avoid contact and prompt
accurate reporting of bighorn/domestic sheep contact or impending contact is essential. Herders are
crucial to ensuring proper management and in maintaining compliance to an exacting standard.
Ultimately the responsibility rests upon the permittees to ensure compliance is being achieved.
General wildlife sighting reporting:
Permittees will be required to report wildlife sightings on the annual actual use form that must be turned
in each fall to the FS/BLM; however bighorn sightings in the proximity of the domestic sheep band must
be reported immediately. If bighorn are seen near or on any FS/BLM sheep and goat allotment, follow
protocol above.
Planned domestic sheep estrus cycle:
The planned breeding season for the domestic sheep operation will not occur during the permitted
grazing season on federal land. This is to lessen the attraction of bighorn rams to domestic sheep ewes
in estrus.
Accountability of Permittee:
x
x
x
Alternative
Permitted domestic sheep stray management 2 3
Extensive efforts will be made by the permittee to remove every authorized domestic sheep from the
Analysis Area following the grazing season. All sheep must be accounted for (dead or alive) as they
enter and exit each allotment, and as they exit the Analysis Area at the end of the season. Special
attention should be given to accounting for sheep at all times. If sheep are unaccounted for, diligent
efforts should be made to locate them as quickly as possible. If the FS/BLM feels that appropriate
efforts are not being implemented, a count-on/count-off inventory will be required as a condition of
operation.
Permittees will be required to respond to reports of stray domestic sheep within 24 hours of notice by the
FS/BLM. Stray domestic sheep will be gathered or disposed of within 72 hours of notification. A followup
report (verbal or written) will be provided to the FS/BLM on time, date and action taken to resolve the
matter; within four days from the notice given by the FS/BLM.
Driveways and trails between grazing areas will be revisited to ensure no stray domestics have been left
behind.
Trailing:
Random on-site compliance monitoring to minimize strays will be conducted by the Forest Service.
Trucking of domestic sheep and goats is preferred to trailing except in situations where risk of contact is
possible (i.e., trucking drop off points in subpopulation areas). In most cases trucking reduces the
chance of stray domestics, and lessens the chance of opportunistic contact by wandering wild sheep.
Domestic sheep will be kept in a tight group during trailing.
Domestic sheep identification:
Permittees will be required to freshly mark (sheep paint) their sheep before they enter onto the National
Forest/BLM. The FS/BLM will coordinate with the permittees annually with specific information regarding
color of paint used in marking their sheep, brands used, ear tags used and colors, earmarks, and other
distinguishing marks or characteristics that may be used in identifying their sheep. In the event, a
x
x
x
x
x
D-28

Silverton Grazing Risk Assessment
permittee does not wish to paint brand their sheep due to conflicts with marketing dye free wool, that
permittee will be assigned a region that they will be responsible for responding to all reports of stray
domestic sheep ( even if it is not their sheep ).
Permit Action:
Repeated non-compliance with domestic sheep stray management PDC will result in appropriate permit
action.
x
D-29

Silverton Grazing Risk Assessment
Figure 1. Bighorn Sheep – Domestic Sheep Overlap in the Silverton Grazing Analysis
Landscape under Alternative 2 (current grazing practices).
D-30

Silverton Grazing Risk Assessment
Figure 2. Bighorn Sheep – Domestic Sheep Overlap in the Silverton Grazing Analysis
Landscape under Alternative 3 (preferred alternative).
D-31

Silverton Grazing Risk Assessment
Figure 3. Ratings for Risk of Physical Contact between Bighorn Sheep and Domestic
Sheep in the Silverton Grazing Analysis Landscape under Alternative 2 (current
grazing practices).
D-32

Silverton Grazing Risk Assessment
Figure 4. Ratings for Risk of Physical Contact between Bighorn Sheep and Domestic
Sheep in the Silverton Grazing Analysis Landscape under Alternative 3 (preferred
alternative).
D-33