The wolverine (Gulo gulo) is a rare intrepid weasel with a fascinating life history tied to snowy places. Populations are slowly recovering in the Cascade Mountains, following human persecution during the 20th century, which likely caused local extinction. Wolverines have naturally recolonized part of their former range in Washington State by dispersing from British Columbia. Presently, biologists estimate the population to be 30-40 individuals within the North Cascades. The number of wolverines across the contiguous United States is estimated to be less than half of carrying capacity. Primary threats to this species include reduced spring snowpack, and changes in land use such as roads, resource extraction, and winter recreation.
Wolverines depend on a deep winter snowpack that lasts into late spring for denning locations where they raise young. The North Cascades are ideal habitat for them. Wolverines are considered an indicator species, meaning that their presence on the Pacific Northwest landscape provides a measure of mountain ecosystem health, as well as connectivity to habitat beyond the Cascades.
