Dolomite of the Upper Cambrian Ottertail (Jubilee) Formation forms a vertical cliff in the headwaters of Dry Gulch Creek, 2.6 kilometres east of Highway 95 and 8.2 kilometres north-northeast of Athalmer. The dolomite continues northwestward for 2 kilometres as a narrow, fault bounded mass lying in limestone and shale of the Cambrian-Ordovician McKay Group.

At Dry Gulch Creek the dolomite is fine grained and grey in colour. The dolomite is reported to be of good grade despite a few white and blue chert nodules. A sample contained 30.59 per cent CaO, 20.54 per cent MgO, 1.88 per cent SiO2, 0.68 per cent Al2O3, 0.28 per cent Fe2O3 and a trace of sulphur (Canada Bureau of Mines Report 811, page 214, Sample 90).