Is the western rattlesnake venomous?

The western rattlesnake is venomous. Medically significant venom. Bites need emergency care and often antivenom. Stay on trails, and check before stepping over rocks and logs.

How do you identify a western rattlesnake?

Blotches with pale edges, becoming bands towards the tail. Dark stripe from the eye back to the jaw, bordered below by a pale line.

Where do western rattlesnakes live?

They are found in 7 US states, in habitats including grassland, rocky, woods and suburban.

Western Rattlesnake

Venomous

Crotalus oreganus · also called northern Pacific rattlesnake, Pacific rattlesnake

The western rattlesnake is the rattlesnake most Californians, Oregonians and Washingtonians will meet — the default rattlesnake of the Pacific states and Great Basin. It turns up on hiking trails, in rocky grassland, and along the edges of suburbs backing onto open country.

Before anything else

Back away and leave it alone. A snake that can see you leaving has no reason to bite. Most bites in the United States happen to people who picked up, cornered, or tried to kill a snake.
Never handle a snake to identify it. Every identification on this site can be made from a photo or from several feet away.
If someone is bitten, call emergency services now. Keep the limb still and below the heart, remove rings and watches, and go to hospital. Do not cut, suck, apply ice, or use a tourniquet — all of these make outcomes worse.
Do not try to catch the snake for identification. A photo from a distance is enough, and hospitals treat symptoms rather than species.

In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.

Venom: Medically significant venom. Bites need emergency care and often antivenom. Stay on trails, and check before stepping over rocks and logs.
Adult length: 24–50 inches (61–127 cm)
Markings: Dark brown blotches with pale borders on an olive, brown or grey ground, becoming crossbands near the tail. A dark stripe runs from the eye to the corner of the jaw.
Habitat: grassland, rocky, woods, suburban
Family: pit viper
Range: 7 US states

How to identify a western rattlesnake

Blotches with pale edges, becoming bands towards the tail.
Dark stripe from the eye back to the jaw, bordered below by a pale line.
Rattle present; head clearly wider than the neck.
The only rattlesnake across most of its northern range, which makes location a strong clue.

What it does when it sees you

Typically rattles and retreats when given space. Most often encountered on warm spring and autumn afternoons and on summer evenings.

What the western rattlesnake is confused with

One test settles each of these.

Gopher snake / bullsnake →

Gopher snakes mimic rattlesnakes convincingly — hissing, flattening the head and buzzing the tail — but have no rattle and a round pupil.

Where it lives

Arizona California Idaho Nevada Oregon Utah Washington

Not sure it was a western rattlesnake? Identify it step by step →