Habitats are varied and include rocky areas of tropical deciduous forest, ocean shores, desert scrub, thorn scrub, open chaparral, mesquite-cactus, and pine-oak woodland, sometimes also dunes, grassland, and cultivated areas between rock outcrops (Grismer 2002, Stebbins 2003, Campbell and Lamar 2004). In southern California, this snake is most common in the western foothills of the Coast Ranges and in dry rocky inland valleys (Ernst 1992, Ernst and Ernst 2003, based on Klauber's studies in San Diego County); it often inhabits areas of granite rock outcroppings, especially in winter (Armstrong and Murphy 1979). In southern Baja California, it is most common in heavy brush where rocks and rocky outcrops are prevalent, but it also occurs in desert and open arid plains (Armstrong and Murphy 1979). This terrestrial snake commonly climbs into low vegetation. Refuges include rock crevices, animal burrows, brush piles, surface debris, or similar sites.

The species' range extends from southwestern California in the United States (from near Pioneertown and Morongo Valley of San Bernardino County and southeastern Los Angeles County) south through Baja California (Mexico), including several islands in the Gulf of California (e.g., Angel de la Guarda, Pond, San Marcos, Danzante, Monserrate, and San Jose islands) and Isla de Santa Margarita and Isla Cedros along the Pacific coast of Baja California to Los Cobos (Murphy et al. 1995, Grismer 2002, Campbell and Lamar 2004). This species does not occur in the desert east of the Sierra de Juarez in northeastern Baja California (Campbell and Lamar 2004). Its elevational range extends from near sea level to about 1,500 m asl but usually below 1,200 m asl (Campbell and Lamar 2004).

Several populations are in protected areas.