This common snake is wide-ranging in California, absent only from the high mountains of the Sierra Nevada, desert regions, and most of the floor of the San Joaquin Valley. Also found on Santa Cruz Island off southern California. Racers are found in many habitat types within their range in California. They are most common in open country and are generally absent from densely forested habitats.
Racers are active diurnal predators and appear to rely heavily on visual cues for prey finding.
In warmer areas brief periods of winter inactivity are spent under such cover, but where winters are colder hibernation is usually passed in the shelter of a rockpile or den within a rocky outcrop. No information on water requirements. They are most common in open country and are generally absent from densely forested habitats. Adults become inactive again in October but juveniles may extend their period of activity until November if conditions are suitable. In milder areas snakes spend brief periods of winter activity under surface objects and no migrations occur.