The western terrestrial garter snake is a harmless snake species that can be found throughout the Western United States. Its five subspecies come in a variety of colors ranging from brown to red, purple, yellow and black.
The 5 subspecies of the western terrstrial garter snake come in various different colors. The most widely distributed subspecies, the wandering garter snake (Thamnophis elegans vagrans) comes mostly in various brown shades while the coastal garter snake (Thamnophis elegans terrestris) can have strong red colors.
All western terrestrial garter snakes have three light-colored longitudinal stripes along their body. Depending on the specimen, geographic area and subspecies, this stripe can be white, yellow, orange or cream-colored. One stripe runs long the center of the back and two on each side of the body. They have strongly keeled scales, giving them a rough appearance. The lower body side is usually brighter colored than the rest of the body. Since its range overlaps with the common garter snake (Thamnophis sirtalis) that also comes in various appearances, the two species are often confused.
The most common subspecies, the wandering garter snake has light-brown or cream-colored stripes and a dark brown body with several darker brown spots. The snake can be confused with the Dekay’s brown snake which can be found in the Eastern United States.
The coastal gartern snake that can be found along the coastal areas of California and Oregon often comes in stronger colors. Its three stripes are white or yellow and the rest of the body can be red or purple with several dark spots.
The mountain garter snake (Thamnophis elegans elegans) is mostly black with white or yellow longitudinal stripes.
Western terrestrial garter snakes are medium sized snakes. Adult snakes reach a length of 20-40 inches (50-100 cm).
The western terrestrial garter snake has a broad food spectrum. They eat anything from fish, slugs, worms, amphibians, mice, rats and even small birds. Generally, they will hold onto their prey and kill it with several strong bites. However, the western terrestrial garter snake is the only garter snake that also uses constriction as a means to suffocate prey. But the snake is everything but an expert in this technique.
Like other species of the garter snake, the western terrestrial garter snake has a mildly toxic saliva that can cause a slight burning or itching sensation for humans or pets. Overall, a bite is not medically significant or dangerous.
Due to its extensive geographic range, the western terrestrial garter snake has adapted to a wide variety of habitats. While most populations live in grasslands, forests, and even mountainous areas, some have even adapted to a semi-aquatic life. All garter snakes have the ability to swim. They inhabit areas from sea level up to elevations of 13,000 feet (almost 4,000 m) in the Rocky Mountains.
Western Terrestrial Garter Snake range in the USA
Subspecies of the western terrestrial garter snake can be found throughout the Western United States. It occurs in the following States: New Mexico, Arizona, Colorado, Utah, California, Nevada, Oregon, Washington, Idaho, Montana, Wyoming and the northeastern tip of Nebraska as well as small populations in the west of North Dakota and South Dakota. The wandering garter snake is the subspecies with the largest distribution.
The following map shows the distribution of the most common subspecies of the western terrestrial garter snake on a map:
Subspecies of Thamnophis elegans
- Thamnophis elegans arizonae – Arizona garter snake
- Thamnophis elegans elegans – mountain garter snake
- Thamnophis elegans hueyi – San Pedro Mártir garter snake
- Thamnophis elegans vagrans – wandering garter snake
- Thamnophis elegans vascotanneri – Upper Basin garter snake
- Thamnophis elegans terrestris – coastal garter snake (or coast garter snake)
Scientific classification of Thamnophis elegans
- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia
- Order: Squamata
- Suborder: Serpentes
- Family: Colubridae
- Genus: Thamnophis
- Species: Thamnophis elegans