It has a distinctive orange or yellow stripe from its head to tail, and the rest of its body is mainly a gray-green color.

[1] The plains garter snake has either an orange or yellow stripe down its back and distinctive black bars on its lip.

[5] The snake's typical diet consists of earthworms, slugs, and small amphibians,[4][6] including the larvae of salamanders.

[6] The plains garter snake is commonly found in meadows and prairies adjacent to water sources, such as marshes, streams, and ponds.

[5] Populations in urban and suburban areas have been greatly reduced due to building activities and pesticide use.

[7] Its habitat range overlaps with that of the common garter snake (Thamnophis sirtalis) in many areas, and it is thought the two species may hybridize.

As the two subspecies share the same habitat in many regions of the United States, further complicated by their strikingly similar appearance, many authorities now do not recognize them.