Central United States and northern Mexico; south from southeastern Wyoming and southern Nebraska through south central United States and into Chihuahua, Durango, Coahuila, Nuevo Leon, and Tamaulipas.
Inhabits grassland, rocky canyons, shrubland, and woodlands. Prefers areas near streams. Although its venom is harmless to humans, it is lethal to its invertebrate prey. Venom is delivered to prey through enlarged teeth in the back of mouth.
Dorsum either tan or cream in color. Black or gray-brown marking on top of head. Pink, red, or orange stripe runs down the center of underside. Body is slender and smooth overall. Head can be hard to distinguish from body; rear upper jaw contains enlarged teeth. Males and females breed in late April and May. Females lay eggs in summer or fall; clutches usually contain 1 to 3 eggs.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians