Stone Mountain Park’s geology is typical of the northern Rocky Mountains’ Eastern Muskwa Ranges. These are characterized by complex folds, wide U-shaped valleys, and rugged peaks of Paleozoic limestone and quartzite.
Compared to the southern Rocky Mountains, the older Muskwa Ranges show evidence of more complex tectonic deformation. Throughout the park, there are examples of tilted sedimentary strata, folds, faults, and synclines.
The park’s topography is steep, with elevations ranging from 1,200 m to 2,500 m. Elevations exceed 2,300 m only in the south of the MacDonald Creek headwaters. At 2,550 m, St. Magnus is the park’s tallest mountain.
Glaciation has been responsible for forming the present-day landscape. The U-shaped MacDonald Valley illustrates this. As glacial ice melted, the area of Summit Lake received immense deposits of gravel and boulders.
This was followed by an intense period of fluvial erosion. As a result, major outwash plains were formed in the headwaters of the North Tetsa River. Five distinct terrace levels indicate the intensity of fluvial action.
Various water bodies are recharged by meltwater in spring, and rain in summer. Summit Lake is the park’s largest body of water. Rocky Crest Lake, a small sub-alpine lake, lies to the west. Between these two lakes is a broad wetland.
Due to its mountainous location, Stone Mountain Park supports only two bio-geoclimatic zones. The subalpine zone is characterized by white spruce, willow, birch, and lodgepole pine.
The alpine tundra zone begins above the 1,500 m mark. Scrub birch and willow species are found along wet areas. Grasses and alpine flowers occur in areas that have enough soil to support them.
On shady sites in the alpine tundra zone, small basins of alpine muskeg occur. Please be careful and avoid these soft, spongy areas, as they are very sensitive to trampling and any kind of disturbance.
The park’s alpine meadows offer opportunities to view the Lapland rosebay shrub, which does not grow any further south. This small shrub is from the rhododendron genus and bears showy clusters of bright rose-purple flowers.
Due to Stone Mountain Park’s high elevations and harsh winters, few fur-bearing mammals live here. Squirrel, hoary marmot, and chipmunk are the most common. Less common species include grizzly and black bear, wolf, coyote, lynx, marten, fisher, and beaver. In the summer, mule deer and elk are present.
Caribou, stone sheep, and mountain goat winter in the park. Caribou and stone sheep are visible along the Alaska Highway. Please reduce speeds and watch for wildlife when travelling on the highway.
Migratory birds congregate along Summit and Rocky Crest Lakes. Raptors, such as golden eagles, can be seen circling the skies. Ptarmigan can often be seen above the treeline.