The Common Ground Snake (Sonora semiannulata) is a species of small, harmless colubrid snake native to the southwestern United States, in Texas, New Mexico, Arizona, Oklahoma, Colorado, Kansas, Missouri, Utah and California, as well as northern Mexico, in Sonora, Chihuahua, Coahuila, Nuevo Leon, and Durango. It is sometimes referred to as the Western Ground Snake, or Variable Ground Snake as its patterning and coloration can vary widely, even within the same geographic region.