Colorado Herpetological Society's

Guide to the Reptiles and Amphibians of Colorado

Blackneck Garter Snake
(Thamnophis cyrtopsis)

Family Colubridae

Photo from Hammerson, 1986.
Used with permission.

Last Updated on January 20, 2000.

Thamnophis cyrtopsis)
Description: Adults 12" to 42" in length. Color olive brown to olive gray; yellow to orange stripe on back, whitish stripes on sides; large black blotches on neck. Moderately slender body; keeled scales. Single anal plate. Elevation Range: Below 6000' in southeastern Colorado; to 6500' in western Colorado. Subspecies in Colorado: Thamnophis cyrtopsis cyrtopsis