Giant Garter Snake

Thamnophis gigas Fitch, 1940

Spanish Name Culebra de Agua Nómada Gigante
Max. Recorded Length 162.6 cm / 64 inches
Range California
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 Giant Garter Snake, Thamnophis gigas, is the largest garter snake species known. Like other large, aquatic species of garter snake, it fills the same ecological niche in western North America that water snakes (Nerodia) fill in eastern North America.


The Giant Garter Snake is listed as threatened by the U.S. Fish and Wildlife Service.

Captive Care

As a federally listed species found only in California, the Giant Garter Snake is not likely to be commonly encountered in captivity. That said, its care requirements are likely not much different from other large, temperamental aquatic garter snakes found on the west coast (such as the Sierra and Two-striped), except, of course, for its larger size. On their captive maintenance difficulty index, where 1 is the easiest and 5 the most difficult, Rossi and Rossi (2003) rate this species a 3.

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.

Perlowin, David. 1994. The General Care and Maintenance of Garter Snakes and Water Snakes. Lakeside CA: Advanced Vivarium Systems.

———. 2005. Garter and Water Snakes. Irvine CA: Advanced Vivarium Systems.

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.