Landforms of British Columbia 1976 - Department of Geography

Galton and MacDonald Ranges are named the Whitefish Range, the southern
extension of the Clarke Range is called the Livingstone Range, and only the Lewis
Range has the same name on both sides of the border.
The Border Ranges lying within British Columbia are the Galton and Mac-
Donald Ranges, and the western part of the Clarke Range.
The Galton Range lies between the Rocky Mountain Trench and the Wigwam
River. Its length between the Elk River and the boundary is 22 miles, and its maxi-
nun width at the south is 8 miles. High peaks OE 7,000 and 7,500 feet rise along a
straight abrupt front above the Trench, whose general terrace elevation is about
3,000 feet. The Galton Range is a comparatively simple synclinal block of late
Proterozoic argillaceous sedimentary rocks bounded by a steep fault-line scarp
along the Rocky Mountain Trench and by the Wigwam fault along the valley of
the Wigwam River.
The ~!4acDonaU Range (see Plate XXXIIB) lies between the Wigwam and
Flathead Rivers and south of the Fernie Basin, whose southern limit is at Lodge-
pole and McLatchie Creeks. The range consists of a number of northwesterIy
trending ridges whose trend is dominated by the northwesterly strike of the sedi-
mentary formations and of the numerous faults.
The highest mountains, with elevations of 7,500 feet, rise above the Wigwam
River valley at 4,000 feet and the Flathead River vaIley at 4,500 feet. This relief
displays moderate, timbered slopes on the argillaceous and silty rocks and steep,
comparatively bare slopes where limestone predominates. For exampIe, there is
considerable contrast between Outlier Ridge, which consists of argillite, siltstone,
and sandstone, Inverted Ridge, which is predominantly limestone, and Trachyte.
Ridge, in which limestone beds are intruded by several syenitic and trachytic
intrusions.
The lower Flathead River valley is eroded in a structural basin underlain by
nearly flat to moderately dipping, poorly consolidated early Tertiary sedimentary
rocks, These rocks extend up to elevations of 6,000 feet, and because of their
poor consolidation produce gentle slopes within the valley.
The Clarke Range (me Plate XXXIIIA) extends eastward from the Flathead
River valley beyond the Alberta-British Columbia Boundary to terminate along
the Lewis thrust in southwestern Alberta, Only the western third of the range
lies in British Columbia.
The range consists of a great thickness (15,000 feet or more) of late
Precambrian sedimentary rocks consisting of argillite, siltstone, sandstone, and
limestone in resistant beds of considerable thickness. These rocks are warped in a
broad synclinal basin lying above the Lewis overthrust, They form bold, massive
mountains to heights of 8,600 feet in British Columbia, with gentle dip slopes and
steep, impressive scarp slopes on resistant formations.
The western edge of the Clarke Range is a fault-line scarp along the Flathead
fault. The mountains descend abruptly to the broad flat valley of the Flathead
River at about 4,500 feet &vation.
The mountains are fretted by wide steep-walled cirques at elevations of 5,500
and 6,000 feet cut into the gently dipping sedimentary rocks of the 7,500- to X,500-
foot mountain summits. These broad cirque basins ,# the heads of wide glaciated
valleys are surrounded by impressive cliffs of Iight-grey limestone and darker
quartz& and argillite, and are an outstanding feature of the Clarke Range.
Tourists in British Columbia are unable to see the natural beauty of the western
part of Clarke Range, but a visit to Waterton Lakes National Park in Alberta offers
an opportunity to see the equally spectacular eastern side of the Clarke Range.
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