Thamnophis sirtalis sirtalis

Common

Moist places. Plains, grasslands, forests, forest edges.

14″ to 48″ long

This is a 14″ to 48″ long, nonvenomous snake. It is the most common snake in Minnesota.

The background color may be brown, greenish, or black. There are 3 pale, yellow, white, or greenish stripes that run the length of the body. The central stripe is often yellow but may be white or greenish, and sometimes has two rows of alternating black spots in a checkerboard pattern. On each side of the central stripe is a row of black spots, which may not be apparent on dark-colored individuals. The lateral stripes are cream-colored to yellow, and are on the third and fourth scale rows up from the belly scales. There is usually a row of black spots below the lateral stripes. Red skin may be visible between the scales when it stretched over recently consumed prey, but there are no red scales.

The head and neck is uniformly dark. The scales above the mouth are the same color as the lateral stripe and have a black border.

The belly color is similar to the stripe color.

Red-sided garter snake (Thamnophis sirtalis parietalis) has bold red bars on the side between the dorsal and lateral scales.

Plains garter snake (Thamnophis radix) central stripe may be entirely orange or orange to the middle becoming yellow. The lateral stripes are on the second and third scale rows up from the belly scales. They prefer dry places.

Lined snake (Tropidoclonion lineatum) is much shorter, only 8″ to 12″ long at maturity. The 3 stripes are off-white. There are 2 rows of dark, half-moon marks on the belly. In Minnesota it has been found only in Blue Mounds State Park.

Eastern ribbon snake (Thamnophis sauritus) tails are longer. The scales above the mouth do not have black borders. It does not occur in Minnesota.

Earthworms, amphibians, leeches, slugs, snails, insects, crayfish, small fish, bird eggs, mice, other snakes, and carrion.

This is one of the most common snakes in Minnesota.