Lava cascade in Thunderbolt Distributary of Labyrinth Cave system

changes: etching and pitting of the crystals
during the late spring and summer
thaw; dust and some organic debris
deposited in the late summer and autumn;
and another clear ice rim added
during the late winter and early spring.
Hoarfrost in the Red Ice Room varies
in appearance from pale pink to white,
depending on the thickness of the rime.
In places, however, so much red dust has
been entrained within the crystals that
they retain their pink color even if removed
from the wall.
Heppe Caves and the
Mammoth Crater­
Hidden Valley Area
A semipermanent supply of ice-cold
water forms a pool, 40 ft wide and
(depending on the season) as much as 12
ft deep, on the floor of a cave 0.5 mi
north of Mammoth Crater (map 19, pl.
6). Attracted by this supply of good
water, Bertha and Earnest Heppe filed a
homestead claim on the land containing
the cave, despite the inhospitable nature
of the surrounding area for agriculture.
This cave and a second cave a short
distance from it became known as the
Heppe Caves. Also, a small agglutinate
cone west of the upper cave was named
"Heppe Chimney." Several years later,
J.D. Howard named a lava-tube cave
lying about 1.5 mi east-southeast of the
Heppe homestead Berthas Cupboard
Cave in honor of Bertha Heppe.
The Heppe homestead was abandoned
long ago, but the old wagon road
that led to the site of their house is still
visible and is used as a trail. It merges
into the main Medicine Lake-Lava Beds
road at a sharp bend 0. 3 mi from the
Heppe Caves. At the west end of the
wagon road a trail descends the south rim
of a steep-sided collapse. From the bottom
of this collapse pit a rock-walled trail
constructed by the Heppes leads deeper
underground by zigzagging down a talus
slope to the surface of the water pool.
Access to Lower Heppe Cave is easily
gained by walking north out of Upper
Heppe Cave into a second very deep
collapse pit (labeled "Central Collapse"
on map 19, pl. 6) surrounded by spectacular
cliffed walls. From Upper Heppe
Cave, cross over the bottom of this deep
pit past Heppe Grotto, and proceed into
the cavernous opening of Lower Heppe
Cave (fig. 66).
At the request of Paul Haertel,
former superintendent of Lava Beds National
Monument, we mapped the Heppe
Caves at a scale of 40 ft to the inch. A
reduced-scale version of this plan is used
an inset on map 19 (pl. 6), but the main
purpose of the map is to depict the source
areas of four major lava dispersal systems
whose lava came from Mammoth
Crater or from the dike-filled fissures
that intersected Mammoth Crater during
the periods of volcanism. The Bearpaw­
Skull lava-tube system also had its
source in a lava lake fed from Mammoth
Crater and its dikes. Donnelly-Nolan and
Champion (1987) preferred the interpre-
Figure 65. Ice stalactites in the Red Ice
Room in Crystal Cave (see fig. 14 and
map 18, pl. 6) composed of 1-in.-diameter
hexagonal ice crystals stacked one
atop another. Figure 66. Entrance to Lower Heppe Cave (see map 19, pl. 6).
Heppe Caves and the Mammoth Crater-Hidden Valley Area 91