THE CENTER FOR NORTH AMERICAN HERPETOLOGY

Reptilia    Squamata (part)    Natricidae  

Sierra Gartersnake
Thamnophis couchii (Kennicott, 1859)
THAM-noh-fiss — KOW-chee-eye

SSAR 9th Edition Comments:
 There are no current SSAR comments for this taxon.

Range maps are based on curated specimens and provided gratis by CNAH.
(Created by Travis W. Taggart; Version: 2025.06.25.15.21.22)
Download GeoJSON polygon range file: - 0.38 MB

Province/State Distribution:
USA: California Nevada

Taxonomic Etymology:
Named for a 19th-century naturalist and military officer.
Thamnophis — From Greek thamnos (θάμνος), “bush” or “shrub,” and ophis (ὄφις), “snake.” The name means “bush-snake” or “shrub-snake,” likely referring to the habitats where these snakes are commonly found.
couchii — A patronym honoring Darius Nash Couch (1822–1897), an American army officer and naturalist who collected extensively in the U.S.–Mexico borderlands and western U.S.

First instance(s) of published English names:
Couch's Garter Snake (Eutaenia couchii: Cooper, James G. 1869. The fauna of California and its geographical distribution. Proceedings of the California Academy of Sciences 4():61-81); Giant Garter Snake (Thamnophis ordinoides couchii: Van Denburgh, John. 1922. The Reptiles of Western North America: An Account of the Species Known to Inhabit California and Oregon, Washinton, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora, and Lower California. Volume I. Lizards. California Academy of Sciences, San Francisco. 556pp.); Sierra Nevada Garter Snake (Thamnophis ordinoides couchii: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Couch's Water Snake (Thamnophis elegans couchii: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Couch's Garter Snake (Thamnophis elegans couchii: Wright, Albert Hazen. 1950. Common names of the snakes of the United States. Herpetologica 6(6):141-186); Sierra Nevada Garter Snake (Thamnophis elegans couchi: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);

Taxon Links:

  
Catalog of American Amphibians and Reptiles
  
The Reptile Database
  
NatureServe
  
iNaturalist
  
GenBank
  
USGS - Nonindigenous Aquatic Species Database

Selected References:
1859 Kennicott, Robert. Eutaenia couchii. Pages in In: Williamson & Abbot, Explorations for a railroad route, from the Sacramento Valley to the Columbia River. U. S. Pacif. Railroad Surv. 10, Pt.4, p. 10. A. O. P. Nicholson, Washington, D.C.. pp.
1903 Brown, Arthur Edwin. The variations of Eutaenia in the Pacific subregion. Proceedings of the Academy of Natural Sciences, Philadelphia 55:286-297
1908 Ruthven, Alexander G. Variations and genetic relationships of the garter-snakes. Bulletin of the United States National Museum (61):1-201
1972 Baker, Robert J., George A. Mengden, and James J. Bull. Karyotypic studies of thirty-eight species of North American snakes . Copeia 1972(2):257-265
1984 Fitch, Henry S. Thamnophis couchii. Catalogue of American Amphibians and Reptiles (351):1-3
1987 Rossman, Douglas A. and G. R. Stewart. Taxonomic reevaluation of Thamnophis couchii (Serpentes: Colubridae). Occaisional Papers of the Museum of Zoology, Louisiana State University (63):1-25
1991 Collins, Joseph T. Viewpoint: A new taxonomic arrangement for some North American amphibins and reptiles Herpetological Review 22(2):42-43
1994 De Queiroz, Alan and Robin Lawson. Phylogenetic relationships of the garter snakes based on DNA sequence and allozyme variation. Biological Journal of the Linnean Society 53:209-229
2002 de Queiroz, Alan, Robin Lawson, and Julio A. Lemos-Espinal. Phylogenetic relationships of North American garter snakes (Thamnophis) based on four mitochondrial genes: How much DNA sequence is enough?. Molecular Phylogenetics and Evolution 22(2):315-329
2014 Crother, Brian I. The bold taxonomic hypotheses of Collins (1991): 23 years later. Herpetological Review 45(2):268-272
2024 Pillod, David S., Michelle I. Jeffries, Robert S. Arkle, and Deanna H. Olson. Climate futures for lizards and snakes in western North America may result in new species management issues Ecology and Evolution 14(10):1-23

THE CENTER FOR NORTH AMERICAN HERPETOLOGY — Accessed: Wednesday 09 July 2025 14:49 CT