This relatively small ecoregion borders on the southeastern edge of the Fraser Lowland and includes the Cascade Mountains that extend into British Columbia from Washington. The mean annual temperature for the area is approximately 9°C with a summer mean of 15.5°C and a winter mean of 2°C. Mean annual precipitation ranges 1200-1500 mm. At lower elevations, the forest cover is composed of stands of western hemlock and Douglas-fir. The subalpine zone is dominated by forests of mountain hemlock, amabilis fir, and some yellow cedar. The small area of alpine tundra is characterized by low-growing shrubs, grasses, and forbs. These mountains reach about 2400 m asl. Humo-Ferric Podzols and Ferro-Humic Podzols are the dominant soils in the ecoregion. Characteristic wildlife includes black-tailed deer, black bear, mink, otter, and grouse. Land uses reflect high recreational and wildlife values at upper elevations and forestry values at lower elevations. The population of the ecoregion is approximately 700.
This ecoregion is part of the Pacific Maritime ecozone.