Dolomite of the Silurian to Middle Ordovician Beaverfoot Formation is exposed over widths of up to 900 metres, south of Fairmont Creek, along the north flank of a ridge extending for 7.5 kilometres eastward from Fairmont Hot Springs to the Kootenay River. The formation is in fault contact to the north with dolomite of the Middle-Upper Cambrian Jubilee Formation and slate, quartzite and conglomerate of the Hadrynian Horsethief Creek Group. Bedding within the dolomite strikes 095 to 110 degrees and dips 45 to 55 degrees north.

The dolomite is fine grained, pale blue and faintly mottled with light grey. A sample of chips collected randomly on a "saddle," just north of Fairmont Mountain and along the slope facing Fairmont Creek analyzed 31.20 per cent CaO, 20.75 per cent MgO, 0.70 per cent SiO2, 0.20 per cent Al2O3, 0.43 per cent Fe2O3 and trace sulphur (CANMET Report 811, page 214, Sample 92).