The three remaining populations of the western gray squirrel (Sciurus griseus) in Washington are isolated and face a number of threats, including habitat loss and degradation, wildfires, highway mortality, and disease. The squirrel occupies oak woodlands and conifer forests in Klickitat and Yakima Counties, low to mid-elevation conifer forests in Okanogan and Chelan Counties, and oak woodlands and conifer forests in Pierce and Thurston Counties.