A dolomite bed of the Middle Cambrian Cathedral Formation is exposed on a switchback on the Yoho River road, 2.6 kilometres northwest of the river's confluence with the Kicking Horse River. The bed continues eastward outcropping along the lower slopes of Mount Ogden. The bed at the switchback is 107 to 122 metres thick, strikes 095 degrees and dips 8 to 18 degrees north.

The upper 76 metres of the bed is comprised of coarse grained, variably mottled dolomite commonly containing small vugs partially filled with calcite. The remaining lower portion of the bed is fine grained and pale blue in colour. The dolomite is massive to thinly bedded and weathers to a brownish grey colour. Occasionally narrow veins of milky white quartz cut the dolomite. Sparsely scattered pyrite occurs in some beds.

A series of chip samples taken in succession across a total stratigraphic thickness of 91.4 metres analysed 30.81 per cent CaO, 20.91 per cent MgO, 0.38 per cent SiO2, 0.33 per cent Al2O3, 0.66 per cent Fe2O3 and trace sulphur (CANMET Report 811, page 191, samples 55, 55A to 55C).