Coastal southern California south to northern Baja California, Mexico; isolated populations exist in La Presa, Baja California.
Usually recognized as one of the most aquatic gartersnakes. Inhabits areas near fresh water usually on rocky terrain. This includes deserts, mountains, woodland, and sage scrub.
Exhibits a brown, olive, brown, or gray dorsum. Can have four rows of smaller dark blotches on either side of body or gray to yellow stripes on either side of body. Possesses a yellow or reddish venter that can be unmarked or darkly marked. Females and males mate from March to April and young are born from July to October. Average litter is 15 young.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians