● Venomous · Native to the United States

Western diamondback rattlesnake

Crotalus atrox (Baird & Girard, 1853)

Also called western diamond-backed rattlesnake
Data updated October 2026

Western diamondback rattlesnake coiled on dry ground, showing pale-edged diamond blotches and a black-and-white ringed tail
Fig. 1 — Adult coiled on dry, rocky ground, with pale-edged diamonds and a banded tail.
Close view of a western diamondback rattlesnake's black and white tail rings and rattle
Fig. 2 — Bold black and white rings just before the rattle.

At a glance

A large, heavy rattlesnake of the Southwest, from Texas and Oklahoma to Arizona and California. It relies on camouflage, often stays silent and still, and uses its rattle as a last-resort warning.

01

Identification

Look for a row of dark, diamond-shaped blotches down the back, each edged in white or cream, over a brown, yellowish-gray, pale blue-gray or pinkish body. Just before the rattle, the tail is circled by sharply contrasting black and white rings. The head is broad and triangular, with dark slanted lines below each eye.

  1. 01Pale-edged diamonds. Dark diamonds outlined in white or cream run the length of the back.
  2. 02Black and white tail rings. Bold, evenly spaced black and white bands right in front of the rattle.
  3. 03Slanted face lines and pits. Dark slanted lines below the eye, a heat-sensing pit between eye and nostril, and vertical pupils.

Commonly confused with

02

Size

01 ft2 ft3 ft4 ft5 ft Typical adult · about 4 ft (122 cm)

Most adults measure 3 to 5 feet (91–152 cm), and large ones reach 6 feet. A few have been recorded at about 7 feet. It is the largest rattlesnake in Oklahoma. Newborns have only a small button at the tail tip and add a rattle segment each time they shed.

03

Range & habitat

Western diamondback rattlesnake resting in the shade of a desert shrub
Fig. 3 — On hot days it rests in the shade of shrubs, rocks or burrows.

Western diamondbacks live across the southwestern United States, in Texas, Oklahoma, New Mexico, Arizona and southeastern California, and through the northern half of Mexico. In Oklahoma they range north to the Kansas line, with well-documented populations in Woods and Alfalfa counties. They are habitat generalists, found in desert, grassland, brushy plains, open woodland, rocky hillsides and coastal areas, from below sea level up to about 6,500 feet (2,000 m). Dry, rocky, shrubby ground with rock crevices and mammal burrows suits them best.

State guides: Texas · Oklahoma

04

Diet & predators

This is a sit-and-wait hunter. It tracks prey by smell and taste, then coils beside a burrow or a well-used rodent trail and waits, using its heat-sensing pits to strike warm-blooded animals even in the dark. Rats, mice, rabbits and gophers make up most meals, along with ground-dwelling birds and lizards. A large meal can last it two to three weeks.

Feeds on

  • Rats and mice
  • Rabbits and gophers
  • Ground-dwelling birds
  • Lizards

Preyed on by

  • Eagles and hawks
  • Roadrunners
  • Kingsnakes
  • Coyotes, bobcats and foxes
Cottontail rabbit sitting in dry grass
Prey — rabbits.
Greater roadrunner standing on open ground
Predator — roadrunner.

05

Behavior & seasons

Western diamondbacks prefer to stay hidden. They rely on camouflage and often stay silent and motionless, since moving or rattling would give their position away. They are reluctant to strike and use the rattle as a last-resort warning, but if pressed one can strike in well under a second. The tail muscles can shake the rattle up to about 60 times per second.

On hot days they rest in the shade of shrubs, rocks, debris or animal burrows, and their heat-sensing pits let them hunt after dark. Activity peaks in spring after they leave winter shelter and again during summer rains, when prey is most active. Winter is spent in caves, rock crevices and burrows. When are snakes active in Texas?

06

Reproduction

Western diamondbacks bear live young. Males court females in spring, soon after leaving winter shelter, and pregnancy lasts about five to six months. Females give birth to 10 to 20 young in late summer, mostly August and September. The mother may stay near her litter for about a week, until the young shed for the first time; after that they scatter to find food and a winter refuge. Young are venomous from birth, and the snakes reach maturity at around three years. They can live more than 20 years.

07

Conservation

The western diamondback is not federally listed and is not considered threatened. It remains widespread and common across much of the Southwest.

08 — Bite safety

If someone is bitten

Western diamondback bites are a medical emergency. Every bite needs medical care. Call 911 or go to the nearest emergency department. For guidance, call Poison Control at 1-800-222-1222. If a pet is bitten, take it to a veterinarian right away.

This page does not give first-aid or treatment instructions. Read our safety disclaimer.

Keep reading

Sources

Data updated October 2026 · How we build these pages