Western Diamondback Rattlesnake
Crotalus atrox
Also called: western diamondback, Texas diamondback
The most common large rattlesnake of the Southwest, found in desert scrub, rocky hills, and grassland from Texas to southern California.
- Kind
- Venomous
- Typical length
- 3 to 5 feet
- Range
- The southern U.S. from Arkansas and Texas west through New Mexico and Arizona to southeastern California
- Regions
- Southwest
- Habitat
- Desert & rocky ground, Grass & prairie
- When active
- Spring through fall, mostly at dusk and night in hot weather
Note: A bite is a medical emergency. In rattlesnake country, never put your hands or feet where you cannot see.
How to identify it
- Dark diamond-shaped blotches with pale borders run down a tan, gray, or brownish body.
- The tail has bold black and white bands just above the rattle, sometimes called a coon tail.
- A pale stripe runs diagonally from the eye to the corner of the mouth.
- The head is broad and triangular.
Often confused with
- Bullsnake: blotched too, and it hisses and shakes its tail in dry leaves to imitate a rattler, but it has no rattle and a narrower head.
- Prairie Rattlesnake: a smaller rattler with oval blotches and no bold tail bands.
If you meet one
- Stop and look before you step. Check where your feet and hands will land, especially near logs, rocks, and brush.
- Back away slowly and give the snake plenty of room, at least several body lengths. It wants to leave, not fight.
- Do not try to kill, catch, move, or photograph it up close. Most bites happen to people doing exactly that, and a dead snake can still bite by reflex.
If someone is bitten
- Move away from the snake and call 911 right away.
- Keep the person calm and as still as possible. Take off rings, watches, and tight clothing near the bite before swelling starts.
- Keep the bitten area still and about level with the heart, and get the person to a hospital. Antivenom is the treatment.
- Do not cut the bite, suck out venom, use a tourniquet, apply ice, or give alcohol. These make things worse.
- In the U.S., Poison Help (1-800-222-1222) can advise while you wait for help. Do not wait to see whether symptoms develop.
Field notes
Western diamondbacks hide under rocks, in rodent burrows, and in brush, and they are active at night in summer heat. A rattle is a warning, so freeze, locate the sound, and back away.
Related guides
This page is a general reference, not medical advice and not a substitute for identifying a real snake with an expert. Many snakes are protected by state law, and rules about killing or handling them vary, so check your state wildlife agency; our state resources directory links to each one. For any bite, get emergency care.