How to Identify the Great Basin Rattlesnake (Identification Guide)

Key identifying features

The Great Basin Rattlesnake (Crotalus oreganus lutosus) is a medium-sized rattlesnake subspecies notable for its pale, muted coloration that closely matches the arid, sun-bleached terrain of the interior Great Basin region. Its blotches tend to appear fainter and less contrasted than in related coastal subspecies, an adaptation to the pale desert soils it inhabits.

Coloration & pattern

The ground color is typically pale gray, tan, or straw-yellow, sometimes with a faint pinkish or brownish cast. A series of dark brown blotches runs along the back, but these tend to be less sharply defined and lower in contrast than in the Northern or Southern Pacific Rattlesnake, often blending more subtly into the pale background. Toward the tail, blotches narrow into bands, followed by the typical black-and-white rings preceding the rattle.

Head, eyes & scales

The head is broad and triangular, with vertical pupils and heat-sensing pits between the eye and nostril, typical of pit vipers. A light diagonal stripe often runs from behind the eye to the jaw. Scales are keeled, and head coloration usually matches the pale body tone.

Size & body shape

Adults typically range from 24 to 40 inches. The body is moderately heavy, tapering to a tail tipped with a segmented rattle, and overall proportions are similar to other members of the western rattlesnake group.

Range & habitat where you'll see it

The Great Basin Rattlesnake occupies the arid interior of the western United States, including much of Nevada, western Utah, southern Idaho, and parts of eastern California and Oregon. It favors sagebrush flats, rocky outcrops, dry grassland, and high desert terrain typical of the Great Basin physiographic region.

How to tell it apart from look-alikes

The Northern Pacific Rattlesnake, found in adjacent and sometimes overlapping range to the west, typically shows darker, more sharply contrasted blotches against a less bleached background. The Speckled Rattlesnake, found further south, has a finer stippled pattern rather than distinct blotches. The pale, low-contrast blotched pattern suited to the light-colored basin soils is the most useful identifying trait separating the Great Basin Rattlesnake from its more boldly marked relatives.