Minnesota has 17 snake species, but only two are venomous: the Timber Rattlesnake and the Eastern Massasauga. These snakes are primarily found in specific regions of southeastern Minnesota, making encounters rare. They are often secretive and prefer to avoid human interaction.
Identifying Minnesota’s Venomous Snakes
Identifying venomous snakes involves recognizing several distinguishing features.
The Timber Rattlesnake measures 31.5 to 48 inches long. Its body color varies from gray to yellow or dark brown, often displaying a distinctive barred or chevron pattern. Its tail is solid black, ending in a segmented rattle. Its head is broad and triangular with a narrow neck, possessing heat-sensing pits between its eyes and nostrils. Its eyes feature vertically elliptical, or cat-like, pupils.
The Eastern Massasauga is smaller, 18.5 to 30 inches in length. This snake has a grayish-brown background with dark brown blotches along its back and smaller spots on its sides. Its tail is ringed with colors similar to its body spots and also ends in a rattle. Like the Timber Rattlesnake, the Massasauga has a spade-shaped head and vertical pupils. Many non-venomous snakes in Minnesota, such as milksnakes or foxsnakes, may mimic rattlesnakes by vibrating their tails, but they lack distinct features like heat-sensing pits, true rattles, or elliptical pupils.
Where These Snakes Are Found
The distribution of venomous snakes in Minnesota is highly localized.
The Timber Rattlesnake is found exclusively in the southeastern counties, particularly within the blufflands and the Mississippi River valley. Habitats include forested bluffs, south-facing rocky outcrops, and bluff prairies. These snakes utilize surrounding forests and agricultural areas as summer feeding grounds. They often den communally in rocky crevices on south and west-facing slopes, returning to these sites year after year.
The Eastern Massasauga is considered endangered in Minnesota, with no evidence of established breeding populations. Past surveys failed to locate the species. Historically, this smaller rattlesnake favored wet habitats such as marshes, bogs, and swamps, as well as adjacent old fields and pastures. The last confirmed record was in 1936.
Safety Measures and Bite Protocol
Encounters with venomous snakes in Minnesota are infrequent, and bites are even rarer. Timber Rattlesnakes are generally docile and will usually try to flee or hide when threatened. If cornered, they often use their rattle as a warning before striking.
To avoid a bite, remain on marked trails, wear sturdy footwear, and avoid reaching into rock crevices or dense vegetation without looking. Always observe snakes from a distance and never try to capture or kill them.
In the unlikely event of a snake bite, immediate medical attention is necessary. Stay calm and call 911 or your local emergency number.
While waiting for help, keep the bitten area still and positioned at or slightly below heart level. Remove any jewelry, watches, or tight clothing from the affected limb before swelling begins. Gently clean the wound with soap and water, then cover it loosely with a clean, dry bandage.
Avoid applying a tourniquet, cutting the wound, attempting to suck out the venom, or applying ice or heat. These actions can worsen the injury or cause further complications.