How to Identify the Western Diamondback Rattlesnake (Identification Guide)
The Western Diamondback Rattlesnake is a large, widespread desert and grassland pit viper identified by its gray-brown diamond pattern and bold black-and-white banded tail just before the rattle.
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Key identifying features
The Western Diamondback Rattlesnake (Crotalus atrox) is a large, heavy-bodied pit viper with a broad triangular head, heat-sensing facial pits, vertically elliptical pupils, and a segmented tail rattle. It is one of the most widespread and frequently encountered rattlesnake species in the southwestern United States and northern Mexico.
Coloration & pattern
The body is typically gray, tan, or brown with a series of dark brown diamond-shaped blotches edged in lighter scales running down the back. A signature feature is the tail, which shows bold alternating black and white (or gray) bands just before the rattle, giving rise to the nickname "coon-tail" pattern in some regions.
Head, eyes & scales
The head is broad and triangular, with two pale diagonal stripes running from behind the eye toward the jaw. Scales are keeled, producing a rough texture, and pupils are vertically elliptical, typical of pit vipers.
Size & body shape
Adults commonly reach 1–1.5 meters (3.3–5 feet), with large individuals occasionally exceeding 2 meters (7 feet). The body is thick and heavily built, tapering to a tail bearing the distinctive banded pattern and rattle.
Range & habitat where you'll see it
This species is widespread across the southwestern United States, including Texas, Arizona, New Mexico, and parts of California, extending into northern Mexico. It inhabits deserts, grasslands, scrubland, and rocky terrain.
How to tell it apart from look-alikes
The bold black-and-white banded tail immediately preceding the rattle is the most reliable feature distinguishing it from other diamond-patterned rattlesnakes, including the Eastern Diamondback Rattlesnake, which lacks such strongly contrasting tail bands and occurs in a separate, non-overlapping southeastern range. Its grayish-brown diamond pattern also tends to be less vividly outlined in cream compared to the Eastern Diamondback.
Frequently asked questions
What is the key tail feature of the Western Diamondback Rattlesnake?
Bold, contrasting black-and-white (or gray) bands on the tail just before the rattle.
How large does it get?
Adults commonly reach 1–1.5 meters (3.3–5 feet), with some individuals exceeding 2 meters (7 feet).
Where is it found?
Across the southwestern United States, including Texas, Arizona, New Mexico, and California, and into northern Mexico, in deserts and grasslands.
How is it different from the Eastern Diamondback Rattlesnake?
It has a more grayish-brown pattern with a distinctly banded tail, and its range does not overlap with the Eastern Diamondback, which occurs in the southeastern U.S.
What color are the diamond markings?
Dark brown diamond-shaped blotches edged in lighter gray or tan scales along the back.
Western Diamondback Rattlesnake identified by the community
Recent Western Diamondback Rattlesnake specimens identified with Snake Identifier.
