Snakes in California: Rattlesnakes and Harmless Species

How many snakes live in California?

California’s snake list includes about 40 native species, though the exact number depends on how scientists divide closely related forms. They live everywhere from foggy redwood forests and coastal sage scrub to the Central Valley, the Sierra Nevada and the hottest deserts in North America. A few, such as the San Francisco garter snake and the southern rubber boa, live nowhere else in the world.

The dangerously venomous snakes are all pit vipers in the genus Crotalus. Like other pit vipers, they have a heat-sensing pit between each eye and nostril, which you can read about in How do pit vipers sense heat?.

Northern and Southern Pacific rattlesnakes

The Pacific rattlesnakes are the ones most Californians are likely to see. The Northern Pacific rattlesnake (Crotalus oreganus oreganus) lives in grassland, chaparral, oak woodland, rocky hillsides and open forest across northern and central California, from the coast to the Sierra Nevada. It is brown to olive or gray with dark, light-edged blotches that turn into bands near the tail. Most adults are 60–100 cm (2–3.3 ft) long, and large ones exceed 1.2 m (4 ft).

The Southern Pacific rattlesnake (Crotalus oreganus helleri, treated by some scientists as its own species) replaces it in Southern California, from the coast to the mountains, and is responsible for many bites there because it lives close to so many people. The Great Basin rattlesnake, a paler form, lives in the sagebrush of the far northeast. All three are subspecies or close relatives of the western rattlesnake.

Red diamond rattlesnake

The red diamond rattlesnake (Crotalus ruber) is a large, brick-red to pinkish-tan rattlesnake with pale-edged diamonds and a black-and-white banded tail. Adults commonly exceed 1 m (3.3 ft), and the largest on record measured about 1.6 m (5.3 ft). In California it lives mainly in the chaparral, coastal sage scrub and rocky desert edges of San Diego and western Riverside counties, extending into neighboring counties and Baja California. It is often described as less quick to rattle and strike than other rattlesnakes, but it must be treated with the same respect.

Desert rattlesnakes: Mojave, sidewinder, speckled and western diamondback

The Mojave rattlesnake (Crotalus scutulatus) of the Mojave Desert is greenish to tan, with diamonds on the back and wide white bands on the tail. Many populations carry Mojave toxin, a powerful nerve-affecting component of the venom, so this species is regarded as one of the most dangerous in North America.

The sidewinder (Crotalus cerastes) is a small, pale rattlesnake of sandy flats and dunes, usually 43–80 cm (17–31 in) long, with a horn-like scale above each eye. It crosses hot, loose sand by throwing its body sideways in loops, leaving J-shaped tracks.

Speckled rattlesnakes live on rocky slopes of the desert mountains, and their speckled colors often match the local rock. Scientists now usually divide them into the southwestern speckled rattlesnake (Crotalus pyrrhus) and the Panamint rattlesnake (Crotalus stephensi) of the Death Valley region and nearby desert ranges. The western diamondback barely reaches California in the far southeast, near the Colorado River.

Rattlesnake behavior and myths

Rattlesnakes eat mainly rodents, rabbits and lizards, and they help control rodent numbers on farms and in wild land. They usually try to stay hidden or crawl away, and the rattle is a warning, not a sign of attack. However, a snake does not always rattle before striking, especially if it is surprised or stepped on; see Do rattlesnakes always rattle before striking?.

A common belief is that young rattlesnakes are more dangerous because they cannot control their venom. The evidence for this is weak; large adults can inject far more venom. Learn more in Are baby rattlesnakes more dangerous?.

Gopher snakes: the classic look-alike

The gopher snake (Pituophis catenifer) is one of the most widespread snakes in California and is often mistaken for a rattlesnake. It is a long, tan or yellowish snake with dark brown blotches, and adults are often over 1.2 m (4 ft) long. When threatened, a gopher snake hisses loudly, flattens its head into a triangle and vibrates its tail against dry leaves. At rest its head is narrow, barely wider than its neck, and it has round pupils and no rattle. Gopher snakes are excellent climbers and burrowers that eat rodents, birds and eggs.

Kingsnakes

The California kingsnake (Lampropeltis californiae) usually has bold dark brown or black and white or cream bands, though some are striped lengthwise. It is famous for eating other snakes, including rattlesnakes, whose venom it resists. It also eats lizards, rodents and birds’ eggs.

The California mountain kingsnake (Lampropeltis zonata) of forests in the mountains is banded in red, black and white. It resembles a coral snake, but California has no coral snakes, and this beautiful, shy snake is harmless.

Garter snakes

California has more kinds of garter snakes (Thamnophis) than most states. They are slender, often striped snakes that live near streams, ponds, marshes and meadows and eat fish, frogs, tadpoles and worms. The common garter snake, profiled in our common garter snake guide, includes the brilliantly colored San Francisco garter snake, which lives only on the San Francisco Peninsula, mainly in San Mateo County, and has been listed as endangered since 1967.

The giant garter snake (Thamnophis gigas) of the Central Valley is the largest garter snake, at 94–165 cm (37–65 in). It depends on marshes and rice fields and is listed as threatened under the US Endangered Species Act. Other species include the aquatic, western terrestrial, Sierra, two-striped, checkered and northwestern garter snakes.

Boas: rubber boa and rosy boa

California has two native boa groups, both small and gentle. The rubber boa (Charina bottae) of northern forests and mountains looks like a smooth, olive-brown rubber toy. When threatened, it rolls into a ball, hides its head and raises its blunt tail, which looks like a second head. The southern rubber boa of the San Bernardino and San Jacinto Mountains is protected as a threatened species by the state.

The rosy boa (Lichanura orcutti) lives in rocky deserts, chaparral and coastal sage scrub of Southern California. It is striped in gray, orange, rust or brown and moves slowly, usually at night.

Other harmless snakes

• Racers and whipsnakes: fast, slender daytime hunters, including the western yellow-bellied racer, the coachwhip and the striped racer. The Alameda whipsnake of the East Bay hills is federally threatened.
• Ring-necked snake: a small, dark snake with an orange neck ring that curls its tail to flash a red-orange underside.
• Sharp-tailed snake: a small snake that specializes in eating slugs.
• Night snake and lyre snake: rear-fanged snakes with mild venom for lizards and small prey; they are not dangerous to people.
• Western threadsnake: a tiny, worm-like burrower that eats ant and termite larvae.

Introduced snakes include the harmless Brahminy blind snake, spread in potted plants, and non-native water snakes released from the pet trade that now live in a few areas, including around Sacramento.

The rare sea snake visitor

The yellow-bellied sea snake (Hydrophis platurus) lives far out in the warm Pacific and Indian oceans and drifts with currents. During unusually warm-water years it is occasionally found on Southern California beaches. It is highly venomous, so a sea snake on the sand should be left alone and reported to lifeguards or wildlife officials.

Where and when to see snakes in California

Snakes are active mainly from spring to fall. In California, rattlesnake bites are most common from April to October. In spring and fall snakes are out by day; in summer heat they move mostly at dusk and at night; and in winter most rest in rock crevices or burrows, though in the south they may bask on warm days. Good places to watch snakes from trails include Pinnacles National Park, Mount Diablo State Park, Joshua Tree National Park and Anza-Borrego Desert State Park. For the desert species next door, see snakes in Arizona.

Staying safe around rattlesnakes

California’s poison control system handles a few hundred rattlesnake bite cases in a typical year, and deaths are rare, usually one or none a year, although 2026 saw an unusual cluster of fatal bites. Across the whole US, the CDC estimates that about 7,000–8,000 people are bitten by venomous snakes each year and about five die.

• Leave snakes alone. Keep several steps away and let the snake move off. Never touch or try to kill a rattlesnake, even one that looks dead.
• Stay on trails, wear boots and long pants, and watch where you put your hands and feet around rocks, logs and brush.
• Carry a flashlight on warm nights and keep dogs on a leash in snake country.
• If someone is bitten, call 911 immediately and get the person to emergency medical care as fast as possible.