A peak at the southern terminus of the Slate Range in Banff National Park, forming the southern buttress of Boulder Pass; the threshold between the Lake Louise corridor and the Skoki backcountry. Redoubt Mountain (2,902 m) has a prominence of 570 m; its parent peak is Mount Richardson. Neighbours include Ptarmigan Peak (2.8 km north-northwest) and Pika Peak. The slopes drain into Hidden Lake and Ptarmigan Lake. Distinguish from Redoubt Peak (3,109 m) near Jasper and Mount Robson.

Geology. The mountain is composed of Middle Cambrian carbonate rocks, primarily the Eldon Formation; massive cliff-forming limestone and dolomite up to 500 m thick that give the peak its fortress-like (castellate) appearance. The Stephen Formation, with its erodible shales and famous trilobite fossils, forms benches and ledges used by scramblers. The sequence was uplifted during the Laramide orogeny.

Naming and first ascent. Arthur Oliver Wheeler (surveyor and Alpine Club of Canada founding member) named the peak in 1908: “redoubt” denotes a small outer fortification, reflecting the squared-off cliffs. The first recorded ascent was in 1906, likely during early ACC exploratory camps; Swiss guides employed by the CPR were active in the Lake Louise area at the time.

Routes. Redoubt is a scramble with two primary options. The Northwest Ridge (Kane route) is accessed from the Skoki Lodge trail via Boulder Pass; it was upgraded from moderate to difficult in later Kane editions due to the technical summit block and route-finding on the ridge; a diagonal breach above Ptarmigan Lake, a rubbly bypass bowl, and a final cliff band. The West Slopes (Spirko route) approaches from the Hidden Lake trail via a steep scree bowl; shorter but involving bushwhacking and loose rock. The “Redoubt Bowl” is a known avalanche terrain. Access via Fish Creek trailhead; base camps at Hidden Lake (Sk5), Baker Lake (Sk11), or Merlin Meadows (Sk18) near Skoki Lodge.

The Slate Range is core grizzly habitat; Parks Canada may enforce group-of-four restrictions in summer. Backcountry permits required.