Mount Mercer is set within Banff National Park, three kilometers east of the Continental Divide, and is situated near the southern end of the Sundance Range which is a subset of the Canadian Rockies.

Located four kilometers east of Assiniboine Pass,[2] Mount Mercer is a remote peak which is not visible from any road.

[1] Precipitation runoff from the mountain drains into Mercer and Bryant creeks which empty to the nearby Spray Lakes Reservoir.

Topographic relief is significant as the summit rises 1,130 meters (3,700 feet) above Bryant Creek Valley in less than 2 kilometers (1.24 mile).

Mount Mercer is composed of limestone which is a sedimentary rock laid down during the Precambrian to Jurassic periods.