The Snakes of Michigan’s St. Clair River

Quick Take

• One snake living along the St. Clair River is frequently misidentified causing people to mistake it for one of North America's most dangerous venomous species. Meet the misidentified watersnake →
• At least one snake here is technically venomous, though its venom can't harm you for a surprising biological reason. Explore the hognose's mild venom →
• One of these species has a range so small it's almost exclusively a Michigan snake, living in the St. Clair region. See Butler's limited range →
• Several of these snakes completely flip their daily schedules depending on the season, and the trigger is not what most people assume.

The St. Clair River flows southward into Lake St. Clair, and together with the Detroit River forms a connecting channel between Lake Huron and Lake Erie. It is a major shipping channel in the Great Lakes Seaway system. It is also a wildlife habitat, a water supply resource, and a popular spot for recreational boating, fishing, trapping, hunting, nature studies, and swimming. One of the river’s notable inhabitants is snakes. While not all species are aquatic, they still need the river to survive. In Michigan, snakes are generally active from early March through late October. Read on to learn more about the snakes of Michigan’s St. Clair River.

1. Eastern Foxsnake (Pantherophis gloydi)

The eastern foxsnake is a species of rat snake. They are large, diurnal (active during the day), nonvenomous constrictors that are native to southwestern Ontario and the eastern Great Lakes region. Their large bodies have yellow or grey skin with dark brown spots along their backs. They also have smaller spots running along the sides of their bodies and pale yellow and black bellies. These heavy-bodied snakes typically measure between 3 and 5.5 feet in length. Eastern foxsnakes are generally found near water and they favor grasslands near marshes, but they can also be found in open woodlands, prairies, and disturbed agricultural areas.

2. Eastern Milksnake (Lampropeltis triangulum)

The eastern milksnake is a nonvenomous snake and a subspecies of the milk snake. They are native to the central and eastern regions of North America. These snakes are docile and non-aggressive, which is why many snake lovers have them as pets. They typically range from 2 to 3 feet, but some may grow larger. These snakes are grey or tan with rows of reddish-brown blotches edged in black. They inhabit areas near wetlands like bogs and marshes, but they also occur in open woodlands, deciduous forests, prairies, meadows, and fields. They are active during the day in the spring and fall, but they are nocturnal during the hottest parts of the summer.

3. Eastern Hognose Snake (Heterodon platirhinos)

The Eastern hognose snake is a rear-fanged, diurnal, mildly venomous snakes. Their venom is only harmful to amphibians, not humans. These snakes occur in the eastern and central U.S. They have thick bodies measuring 2-3 feet in length. These snakes have upturned snouts that help them dig burrows. Colors include orange, red, brown, green, black, grey, or a mixture of these colors depending on their habitat. They can also have checkered or blotched patterns, but sometimes they are just one solid color. Their bellies are typically solid gray, yellow, or cream. While they are more common in other parts of the state, these snakes have been observed in areas with sandy soils near the St. Clair River.

4. Common Watersnake (Nerodia sipedon)

The common watersnake occurs in aquatic habitats all over North America. They are large, nonvenomous snakes that generally range from 2 to 3.5 feet in length. These snakes vary in color from dark brown to black, grey, or red. They have dark blotches on their bodies and brownish-black crossbands on their necks. As they get older, their color darkens, making the patterns fade into the background. Their bellies vary from gray, white, or yellow. They are sometimes mistakenly identified as cottonmouths, which are highly venomous. Common watersnakes are often seen basking on logs, rocks, or overhanging branches near rivers, streams, lakes, and marshes. They are diurnal in spring and fall but become primarily nocturnal during the summer.

5. Dekay’s Brownsnake (Storeria dekayi)

The Dekay’s brownsnake is easy to identify because of its simple brown or grey color pattern with a center stripe and two rows of black spots down the length of its body. These small, nonvenomous snakes typically measure 9 to 13 inches in length. They have a broad range across the eastern U.S. These elusive snakes inhabit riparian areas, moist woodlands, marshes, and wet meadows. They also occur in urban and suburban areas like yards, gardens, and parks. They are typically diurnal in spring and fall, but they are generally nocturnal or crepuscular (active at dawn and dusk) during the summer.

6. Red-Bellied Snake (Storeria occipitomaculata)

The red-bellied snake has a wide distribution across eastern North America. They are small, nonvenomous snakes, typically measuring between 8 and 12 inches long. Their colors can include black, tan, olive, brown, or grey on top with bright orange, pink, or red bellies. They are common throughout Michigan, inhabiting moist woodlands, marshes, bogs, and hiding under debris in suburban areas. These snakes are diurnal in spring and fall and nocturnal in summer.

7. Butler’s Garter Snake (Thamnophis butleri)

Butler’s garter snakes are relatively small, nonvenomous snakes typically measuring 15–22 inches. Their base color ranges from black to olive brown, with two rows of dots running down their backs. These slender snakes also have three orange-to-yellow stripes that run down their bodies. Butler’s garter snakes have a small, patchy range only in the southern Great Lakes region, with the highest concentration in southern Michigan. Butler’s garter snakes prefer habitats like wet prairies, savannas, marshes, meadows, and grasslands. They are generally diurnal and are often basking in the morning, but they become nocturnal during the summer.

8. Common Garter Snake (Thamnophis sirtalis)

The common garter snake is found throughout North America. This snake varies in color, including shades of gold, blue, green, yellow, red, black, and brown. They may also have stripes and a checkered pattern. These nonvenomous snakes generally measure from 18 to 30 inches, but they can grow to 54 inches. The common garter snake is frequently seen near the St. Clair River, favoring marshes, damp grassy areas, and backyards on the water. They are primarily active during the day but may become nocturnal to avoid extreme heat in the summer.