A few small cirque glaciers are found at the highest elevations. Black spruce forest vegetation dominates some hills and ridges. Forests of white spruce, paper birch, and alder cover low hills along major rivers. Mountain soils are formed in very stony and gravelly colluvium material over bedrock. Valley soils are formed over glacial till.
Permafrost occurs sporadically.
Blackpoll warblers are common breeders in conifer stands in river valleys. Wood frogs have been reported. Sockeye salmon are the most abundant fish, but chum, king, and silver salmon are also numerous.