Range Description

The species' range extends from southern British Columbia, Idaho, Utah, Colorado, and Kansas southward through the southwestern United States to southern Baja California (including Isla Partida Norte, in the Gulf of California) and Guerrero in mainland Mexico, at elevations from near sea level to around 2,650 m asl (8,700 feet) (Stebbins 2003). Reports of occurrences as far south as Costa Rica (e.g., Ernst and Ernst 2003) are incorrect (Savage 2002).