Mountain soils formed in very stony and gravelly colluvium material over bedrock, whereas valley soils formed in glacial till. Potential Natural Vegetation. Alpine tundra heath meadows and barrens predominate in the mountains, whereas moist tundra sedge-tussock meadows occur in valley bottoms. Black spruce forest vegetation dominates some hills and ridges. Forests of white spruce, paper birch, and alder cover the low hills along the major rivers.
Blackpoll warblers are common breeders in conifer stands in river valleys.
Beaver are abundant, supporting a large annual harvest. Wood frogs have been reported to occur. Sockeye salmon are the most abundant fish. Chum, king, and silver salmon are also numerous. Rainbow trout are a common resident fish in this Section.