Common Garter Snake
Thamnophis sirtalis
Extreme variability in coloration depending on location & individual. Most individuals have pattern of yellow, white, or tan stripes on a brown, black, or green backgroun…
How to identify
Extreme variability in coloration depending on location & individual. Most individuals have pattern of yellow, white, or tan stripes on a brown, black, or green background. Some populations have spots or mottled patterning. Average adult length is 22 inches, but may reach up to 54 inches long.
Range
Found throughout most of the continental United States, into Canada and small population occurs in north central Mexico. Absent from Utah, Nevada, and Arizona.
Habitat
Wide range of habitats include fields, forests, prairies, wetlands, marshes, and grasslands. Usually found near water.
Variations
Coloration varies vastly depending on region, currently 13 recognized subspecies. Colors can include green, blue, yellow, gold, orange, red, brown, and black. Some individuals have spots, or mottled patterns of varying colors, while others are solid color with uninterrupted ventral stripes.
Similar species
Name and etymology
Sirtalis: New Latin for like a garter.
More illustrations
Maritime Garter Snake
Eastern garter snake
Red-sided Gartersnake
At a glance
Size
46 to 137 cm
Range
Found throughout most of the continental United States, into Canada and small population occurs in north central Mexico. Abse…
Habitat
Wide range of habitats include fields, forests, prairies, wetlands, marshes, and grasslands. Usually found near water.
Range map
Approximate range. © Mapbox © OpenStreetMap