This ecoregion includes the Richardson and British mountains, located in the northern Yukon. This ecoregion is marked by short, cool summers. Winters are generally extremely cold, although winters at higher elevations are more moderate during frequent periods of temperature inversion. Major mountain passes can be subject to strong outflow winds, causing severe wind chill conditions. The mean annual temperature for the area is approximately -10°C with a summer mean of 6.5°C and a winter mean of -25°C. Mean annual precipitation ranges from 300 mm in the northwest to approximately 400 mm in the southeast. This ecoregion is characterized by alpine tundra at upper elevations and subalpine open woodland vegetation at lower elevations. Alpine vegetation consists of lichens, mountain avens, intermediate to dwarf ericaceous shrubs, sedge, and cottongrass in wetter sites. Barren talus slopes are common. Subalpine vegetation consists of discontinuous open stands of stunted white spruce in a matrix of willow, dwarf birch, and Labrador tea. Sedge, cottongrass, and mosses occur in wet sites. The highest latitudinal limit of tree growth (white spruce) in Canada is reached in this ecoregion. The northern unglaciated Richardson and British mountain ranges reach 1675 m asl in the region's northern core. The southern Richardson ranges exhibit smooth, rounded profiles composed almost entirely of folded, sedimentary strata of Cambrian- and Palaeozoic-age rocks. The ecoregion includes a small portion of unglaciated plateau physiography composed of Tertiary sediments. Turbic Cryosols with Static Cryosols developed on colluvial and alluvial deposits are dominant. Low ice content continuous permafrost predominates in the southern half of the region with the ice content increasing in the northern half and towards the Alaska border. Limestone rock outcrops are significant. Magnificent examples of periglacial landforms, particularly cryoplanation summits and terraces exist in sedimentary rocks of the Richardson Mountains. Characteristic wildlife includes caribou, grizzly bear, Dall's sheep, moose, snowshoe hare, fox, and arctic ground squirrel. The ecozone is within the annual migration range of the Porcupine caribou herd. There are no permanent settlements within the ecoregion, and land uses are restricted to subsistence wildlife trapping and hunting. Recreation and tourism activities are associated with Ivvavik National Park which covers most of the British Mountains.
This ecoregion is part of the Taiga Cordillera ecozone.