This species occurs in southwestern Canada and northwestern United States. Its range includes southwestern British Columbia, western Washington, western Oregon, and extreme northwestern California, including various coastal islands, at elevations from sea level to around 1,680 m (5,500 feet) (Nussbaum et al. 1981, Brown et al. 1995, Rossman et al. 1996, Ernst and Ernst 2003, Stebbins 2003).