A peak in the Slate Range of Banff National Park, south of Skoki Mountain and north of Brachiopod Mountain. Fossil Mountain (2,946 m) has a prominence of 471 m; its parent peak is Mount Richardson. The mountain is flanked by Ptarmigan Lake (west) and Baker Lake (east).

Geology and fossils. The peak sits within the Skoki Formation; Early to Middle Ordovician dolomite and limestone (~488–461 million years ago) named by Charles Doolittle Walcott in 1928. The slopes are rich in marine invertebrate fossils: brachiopods, gastropods, cephalopods, trilobites, corals, and crinoids; products of the Ordovician Radiation. Fossil removal is prohibited; the Canada National Parks Act protects all natural objects in situ.

First ascent and naming. Morrison Parsons Bridgland (1878–1948), Dominion Land Surveyor and Alpine Club of Canada co-founder, made the first recorded ascent in 1906 and named the peak for the abundance of fossils. His party included Gottfried Feuz (Swiss guide), Rev. George Kinney, J.D. Patterson, and P.D. McTavish. Bridgland used phototopographical techniques (1902–1930) to produce the first detailed maps of the Rockies; his summit cairns and images now support the Rocky Mountain Repeat Photography Project tracking glacial retreat.

Avalanche history. Fossil Mountain has claimed lives in two notable incidents. On 7 April 1933 Raymond Paley, an MIT mathematician and Royal Society fellow, was killed in a slab avalanche while skiing; the first recorded skiing fatality in the Canadian Rockies. He was a guest at Skoki Lodge; the tragedy contributed to the Whytes’ departure. In February 1988 cousins Dan and Wayne Hugo were killed in an avalanche while hiking and skiing. The mountain’s scree slopes form terrain traps that can release unexpectedly; Avalanche Canada bulletins and proper equipment are essential for winter travel.

Routes. The standard ascent is an easy scramble (Alan Kane): ~25.6 km round trip, ~1,250 m gain, from Fish Creek via Temple Road, Boulder Pass, and Deception Pass to the broad west slope. Many use Baker Lake or Hidden Lake campgrounds. In winter the peak is a ski-touring objective accessible from Skoki Lodge. The Slate Range is core grizzly habitat; backcountry permits and group-size recommendations apply.