A Guide to the Amphibians
and Reptiles of California

Valley Gartersnake - Thamnophis sirtalis fitchi

Fox, 1951
Click on a picture for a larger view

Common Gartersnakes California Range Map
Range in California: Orange

Click the map for a guide to the other subspecies.

observation link

Valley Gartersnake Valley Gartersnake Valley Gartersnake Valley Gartersnake
Adult, American Basin, Sacramento County Adult, Sierra Nevada foothills,
Calaveras County
Adult, Plumas County
Valley Gartersnake Valley Gartersnake Valley Gartersnake Valley Gartersnake
Adult, 4,000 ft., Klamath Basin,
Siskiyou County
Adult, 4,000 ft., Sierra County
© John Stephenson
Adult, Butte County
© Jackson Shedd
Adult, San Benito County.
Coast Gartersnake Coast Gartersnake Coast Gartersnake Valley Gartersnake
Adult, northern Humboldt County Adult, Fresno County © Patrick Briggs
California Red-sided Gartersnake California Red-sided Gartersnake California Red-sided Gartersnake Valley Gartersnake
Adult, Napa County © Jonathan Koehler
This snake was found along the Napa River south of Yountville, which is close to where the T. s. infernalis subspecies meets the T. s. fitchi subspecies in Napa County. It looks more like T. s. infernalis to my eye, but some might call it an intergrade due to the fact that the entire head is not red.
Adult, Fresno County © Brett Burch
Valley Gartersnake Valley Gartersnake Valley Gartersnake  
Adult, Del Norte County © Alan Barron Adult, Del Norte County © Alan Barron
Adult, approx. 9,000 ft. elevation,
Shasta County © Kurt Geiger
Unusual Color or Pattern
Valley Gartersnake Valley Gartersnake Valley Gartersnake Valley Gartersnake
Melanistic adult, Yolo County © Richard Porter
Valley Gartersnake Valley Gartersnake    
This unusually-colored adult was found eating a California Toad in Upper Lake, Lake County. Possibly axanthic (missing red pigment) it might also represent an intergrade with T. s. infernalis, which sometimes has blue coloring.
© Yuri Brezinger
Valley Gartersnakes From Outside California
Valley Gartersnake
Adult, Klickitat County, Washington
Valley Gartersnake Valley Gartersnake Valley Gartersnake Valley Gartersnake
Underside of adult,
Klickitat County, Washington
Juvenile, Kittitas County, Washington
In some areas, Valley Gartersnakes overwinter in large groups. Here you can see a mass emergence of Valley Gartersnakes and Wandering Gartersnakes in early May, Lincoln County, Wyoming. © Leslie Schreiber Adult with considerable red coloring on the side of the head, Skagit County, Washington © Zachary Lim
Identification Tip
  Puget Sound Gartersnake  
  Looking at the top of the heads can help to identify these sympatric species on the north coast:

T. sirtalis - Common Gartersnake (Left) has a larger longer head with bigger eyes than T. ordinoides - Northwestern Gartersnake (Right.)

© Filip Tkaczyk

California Gartersnakes Identification Key
Valley Gartersnakes Feeding
Coast Gartersnake Coast Gartersnake Coast Gartersnake Coast Gartersnake
Coast Gartersnake Coast Gartersnake Coast Gartersnake Coast Gartersnake
Adult Valley Gartersnake eating a Boreal Toad in Trinity County © Spencer Riffle

Valley Gartersnake Valley Gartersnake Valley Gartersnake Valley Gartersnake
Adult snake eating a California Toad.
© Pamela Greer
Adult Valley Gartersnake found attempting to eat a non-native leopard frog of unknown species in a suburban backyard in Fresno County. (The frog survived, but died later.) 
© Stephanie Mastriano
This unusually-colored adult was found eating a California Toad in Lake County. © Yuri Brezinger
Valley Gartersnake Habitat Valley Gartersnake Habitat Valley Gartersnake Habitat Valley Gartersnake Habitat
Trinity Mountains habitat,
5,800 ft., Siskiyou County
Coastal habitat, Humboldt County Habitat, 4,000 ft., Klamath Basin,
eastern Siskiyou County
Habitat, Yolo County © Richard Porter
Valley Gartersnake Habitat Valley Gartersnake Habitat Valley Gartersnake Habitat  
Habitat, agricultural canal,
Sacramento County
Habitat, 400 ft., Butte County Habitat, Yuba County  
Short Videos
Valley Gartersnake Valley Gartersnake Valley Gartersnake  
A Valley Gartersnake is discovered resting in the sun near the edge of a mountain pond which is still half-surrounded by snow. When I get too close, the snake races off, showing the speed with which this gartersnake can crawl and swim to safety. Valley Gartersnakes race over land and in water at a high-elevation pond in Siskiyou County. A Valley Gartersnake at a creek in the Plumas County mountains.  

Not Dangerous (Non-poisonous)  -  This snake does not have venom that is dangerous to most humans.

Gartersnakes have toxins in their saliva which can be deadly to their prey and their bite might produce an unpleasant reaction in humans, but they are not considered dangerous to humans.

Adults of this species measure 18 - 55 inches in length (46 - 140 cm), but the average size is under 36 inches (91 cm).

A medium-sized snake with a head barely wider than the neck and keeled dorsal scales.

The eyes are relatively larged compared with other gartersnake species.

Some average scale counts:
7, occasionally 8, rarely 6 or 9, upper labial scales, often with black wedges.
10 lower labial scales.
The rear pair of chin shields are longer than the front.
Average of 19 scales at mid-body.
Color and Pattern
The ground color is dark gray, black or brown.
The dorsal stripe is wide and yellowish, and there is a yellowish stripe along the bottom of each side.
The red on the sides of this Common Gartersnake are usually confined to the area just above the lateral stripes, in a single row, alternating with dark markings
.The top of the head is dark - black, dark gray, or brownish. There is sometimes a bit of red on the sides of the head.
The underside is bluish gray, and it may become darker toward the tail, or may become paler.
Key to Identifying California Gartersnake Species

Life History and Behavior

Primarily active during daylight.
A good swimmer.
Often escapes into water when threatened.
The species T. sirtalis is capable of activity at lower temperatures than other species of North American snake.
When first handled, typical of gartersnakes, this snake often releases cloacal contents and musk, and strikes.
Diet and Feeding
Eats a wide variety of prey, including amphibians and their larvae, fish, birds, and their eggs, small mammals, reptiles, earthworms, slugs, and leeches.

This species is able to eat adult Pacific newts (genus Taricha) which are deadly poisonous to most predators.
There is evidence * that when Common Gartersnakes (Thamnophis sirtalis) eat Rough-skinned Newts (Taricha granulosa) they retain the deadly neurotoxin found in the skin of the newts called tetrodotoxin for several weeks, making the snakes poisonous (not venomous) to predators (such as birds or mammals) that eat the snakes. Since California Newts (Taricha torosa) also contain tetrodotoxin in their skin, and since gartersnake species other than T. sirtalis also eat newts, it is not unreasonable to conclude that any gartersnake that eats either species of newt is poisonous to predators.

* (Williams, Becky L.; Brodie, Edmund D. Jr.; Brodie, Edmund D. III (2004). "A Resistant Predator and Its Toxic Prey: Persistence of Newt Toxin Leads to Poisonous (Not Venomous) Snakes." Journal of Chemical Ecology. 30 (10): 1901–1919.)
Mating occurs in the spring (and possibly the fall ) and young are born live, spring to fall.

Utilizes a wide variety of habitats - forests, mixed woodlands, grassland, chaparral, farmlands, often near ponds, marshes, or streams. 

Geographical Range
The species Thamnophis sirtalis - Common Gartersnake, has the largest distribution of any gartersnake, ranging from the east coast to the west coast and north into Canada, farther north than any other species of snake in North America.

This wide-ranging subspecies, Thamnophis sirtalis fitchi - Valley Gartersnake, is found throughout all of northern California, including the coast in Humboldt and Del Norte Counties, south, east of the north and south coast ranges through the Great Valley and much of the Sierra Nevada (excluding a large part of the interior part of the San Joaquin Valley alley) and east of the Sierra Nevada into the northern part of the Owens Valley Outside of California. T. s. fitchi ranges north all the way to extreme southern Alaska, and east into western Nevada, Idaho, western Montana, western Wyoming, and northcentral Utah.

Rossman et al. in The Garter Snakes - Evolution and Ecology 1996 * show T. s. fitchi ranging along the central coast from south of Monterey Bay to Santa Barbara County. Robert Stebbins, in his 2003 western field guide, shows T. s. infernalis along the central coast with an intergrade zone around Ventura County. I have chosen to show T. s. infernalis ranging along the south coast with no intergrade zone, after personal commications that told me the T. sirtalis in that area show characteristics of T. s. fitchi, but are still T. s. infernalis, however I remain skeptical and wait for more information.

Full Species Range Map
Elevational Range
Rossman et al (1996) show the elevation record for the species (not specifically this subspecies) at 8,333 feet (2540 m.). Stebbins (2003) shows it as
8,000 ft. (2,438 m).

Notes on Taxonomy
SSAR Herpetological Circular No. 43, 2017 shows this note regarding the species Thamnophis sirtalis: "Analyses of mitochondrial and nuclear data suggest that this species may be composed of multiple independently evolving lineages often not concordant with the subspecific taxonomy (F. Burbrink, pers. comm.)."


Alternate and Previous Names (Synonyms)

Thamnophis sirtalis fitchi - Valley Garter Snake (Stebbins 1966, 1985, 2003, Stebbins & McGinnis 2012)
Thamnophis sirtalis fitchi (Stebbins 1954)

Cascade garter snake
Northwestern garter snake
Callifornia garter snake
Pacific garter snake
Red-barred garter snake

Conservation Issues  (Conservation Status)
Family Colubridae Colubrids Oppel, 1811
Genus Thamnophis North American Gartersnakes Fitzinger, 1843
Species sirtalis Common Gartersnake (Linnaeus, 1758)

fitchi Valley Gartersnake Fox, 1951
Original Description
Thamnophis sirtalis - (Linnaeus, 1758) - Syst. Nat., 10th ed., Vol. 1, p. 222
Thamnophis sirtalis fitchi - Fox, 1951 - Copeia, p. 264

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Thamnophis - Greek - thamnos - shrub or bush, and ophis - snake, serpent
- sirtalis like a garter - probably refers to the to striped pattern
fitchi - honors Fitch, Henry Sheldon

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Other California Gartersnakes
T. a. atratus - Santa Cruz Gartersnake
T. a. hydrophilus - Oregon Gartersnake
T. a. zaxanthus - Diablo Range Gartersnake
T. couchii - Sierra Gartersnake
T. gigas - Giant Gartersnake
T. e. elegans - Mountain Gartersnake
T. e. terrestris - Coast Gartersnake
T. e. vagrans - Wandering Gartersnake
T. hammondii - Two-striped Gartersnake
T. m. marcianus - Marcy's Checkered Gartersnake
T. ordinoides - Northwestern Gartersnake
T. s. infernalis - California Red-sided Gartersnake
T. s. tetrataenia - San Francisco Gartersnake

More Information and References
California Department of Fish and Wildlife

* Rossman, Douglas A., Neil B, Ford, & Richard A. Siegel. The Garter Snakes - Evolution and Ecology. University of Oklahoma press, 1996.

Stebbins, Robert C., and McGinnis, Samuel M.  Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.

Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Snakes of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Bartlett, R. D. & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.

Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997.

Ernst, Carl H., Evelyn M. Ernst, & Robert M. Corker. Snakes of the United States and Canada. Smithsonian Institution Press, 2003.

Wright, Albert Hazen & Anna Allen Wright. Handbook of Snakes of the United States and Canada. Cornell University Press, 1957.

Conservation Status

The following status listings are copied from the April 2018 Special Animals List and the 2017 Endangered and Threatened Animals List, both of which are published by the California Department of Fish and Wildlife.

If no status is listed here, the animal is not included on either CDFW list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status, you can go to the NatureServe and IUCN websites to check their rankings.

Check here to see the most current complete lists.

This snake is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.
Status Listing
NatureServe Global Ranking
NatureServe State Ranking
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife None
Bureau of Land Management None
USDA Forest Service None


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