Western and south central United States and most of northern Mexico; starts as far west as Oregon and eastern and southern California and continues eastward through southern Idaho, Utah, western Colorado, Nevada, Arizona, New Mexico, and western Texas. Exists in most of northeastern and north central Mexico.
Especially prefers desert areas with many rodent burrows and some ground vegetation. Avoids areas with dense vegetation that will prevent running. Although spends most of its time on the ground, some individuals can be found in bushes when threatened. Diet includes spiders, lizards, insects, small mammals, and some plant material.
Males have an average snout vent length of 12 cm (4.8 in) while the female has an average snout vent length of 15 cm (5.8 in). Undergoes two distinct color phases: the "light phase" during which the base color is gray, yellow, or brown, and the "dark phase" during which the base color is brown and exhibits lighter blotches and bands. Belly is usually light; throat usually exhibits gray blotches. Young have rust-colored markings on back and red and yellow markings on thighs and under tail. Females lay eggs between May and June; on average, clutches range from 1-11 eggs.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians