Sierra Garter Snake

Thamnophis couchii (Kennicott, 1859)

Alternate Name Western Aquatic Garter Snake
Spanish Name Culebra de Agua Nómada de Sierra Nevada
Max. Recorded Length 95.7 cm / 37.7 inches
Range California, Nevada
Pet Trade Availability ★☆☆☆ rarely available
Captivity Rating ★★☆☆ fair

Note: These species pages are in various stages of completion. Some are basically finished; others are very much under construction. Please be patient while I work on this section.

The Sierra Garter Snake is one of several large, primarily aquatic species found on the west coast of North America. Found in California and Nevada, it feeds mostly on fish, including trout, as well as on amphibians, both larvae and newly transformed adults.


(To come. Only found in California and Nevada.)

Captive Care

This species has a reputation for being bad-tempered and willing to bite. Small wonder it’s not often kept in captivity, even by garter snake standards. I’ve never had the pleasure of encountering one.

Rossi and Rossi (2003) report that they have kept Sierra garters successfully, and say that they can be cared for the same way as other garter snakes. On their captive maintenance difficulty index, where 1 is the easiest and 5 the most difficult, they rate this species a 3.

Sierra garters prefer to eat fish. Rossi and Rossi report some success at getting them to eat fish-scented mice; specimens kept by Rossman et al. (1996) refused. It’s probably safe to say that you shouldn’t keep this species unless you’re prepared to deal with a fish-based diet and its complications.

If you have experience with this species and would like to share, please contact me.

For general information on keeping garter snakes in captivity, please see the Care Guide.

Articles and News


Bartlett, R. D. and Alan Tennant. 1997. Snakes of North America: Western Region. Houston: Gulf.

Brown, Philip R. 1997. A Field Guide to Snakes of California. Houston: Gulf.

Ernst, Carl H. and Evelyn M. Ernst. 2003. Snakes of the United States and Canada. Washington: Smithsonian Books.

Rossi, John V. and Roxanne Rossi. 2003. Snakes of the United States and Canada: Natural History and Care in Captivity. Malabar FL: Krieger.

Rossman, Douglas A., Neil B. Ford and Richard A. Seigel. 1996. The Garter Snakes: Evolution and Ecology. Norman OK: University of Oklahoma Press.