Columbia Mountains

a group of mountain ranges (Cariboo, Monashee, Selkirk, and Purcell) in the inner belt of the Canadian Cordillera between 48° and 54° N lat.

To the east the Columbia Mountains are bordered by a narrow tectonic depression called the Rocky Mountain trench; to the west they adjoin the Fraser and Kamloops plateaus. The mountains are composed primarily of Precambrian massive crystalline rocks. They are deeply dissected, mainly by longitudinal river valleys; there are many dammed lakes. Many of the peaks are over 3,000 m in elevation; the highest is Mount Sir Wilfrid Laurier, 3,581 m. Glacial forms of relief are typical; the modern glaciers are large. Altitude belts of forest-steppe, coniferous subalpine forests, alpine meadows, rocks, and glaciers are well pronounced in the Columbia Mountains. On the damper western slopes at an altitude of 750–1,200 m a belt of luxuriant coniferous forest (the Columbia Forest) has developed. Glacier National Park is in the Selkirk range.