Mount Stephen, 3,199 m (10,495 ft), is a mountain located in the Kicking Horse River Valley of Yoho National Park, ½ km east of Field, British Columbia, Canada. The mountain is mainly composed of shales and dolomites from the Cambrian Period, some 550 million years ago. The Stephen Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin was first described at the mountain and was named for it. Stephen has a subpeak known as Stephen SE1, at the end of a 1 km ridge, 132⁰ from the main peak, visible from Lake O'Hara.
The main route (a scramble) ascends slopes on the southwest face but requires much route finding and the final section of 125 m (410 ft) to the top is rated difficult. A cornice on the summit may prevent parties from reaching the top so if in doubt of conditions, attempts should wait until August. The route also passes through a fossil bed and thus requires a special park permit to be in the area. The elevation gain is 1,920 m (6,299 ft).
For rock climbers, a route on the north ridge is rated III 5.7 with generally good rock formations composed mainly of quartzite.