Rattlesnakes are present in Minnesota, though they are rare. The state is home to a small, isolated population of these specialized reptiles, found exclusively in the unique blufflands of the far southeastern corner. Due to this highly localized distribution, encounters with them are uncommon.
Minnesota’s Rattlesnake Species
The single species of rattlesnake with a stable, breeding population in Minnesota is the Timber Rattlesnake (Crotalus horridus). It is one of only two venomous snakes found in the state, typically reaching lengths between 31 and 48 inches.
Their coloring is variable, ranging from gray or yellow to dark brown, marked with distinctive dark, chevron-shaped crossbands. The tail is a unique, solid black feature, often giving the snake the common name “velvet-tail.” This tail ends in the segmented rattle that produces the characteristic warning sound.
The head is broad and distinctly triangular, a shape created by the venom glands located behind the eyes. A Timber Rattlesnake is classified as a pit viper, possessing heat-sensing facial pits between the eye and the nostril. These specialized features are important for distinguishing them from harmless snakes in the same region.
Geographic Range and Preferred Habitat
The Timber Rattlesnake’s range in Minnesota is restricted to the southeastern blufflands, an unglaciated region often referred to as the Driftless Area. Their distribution is localized to the counties bordering the Mississippi River, including Houston, Fillmore, Winona, and Wabasha counties.
They depend on the south-facing slopes of limestone bluffs for survival. These slopes feature rocky outcrops and ledges essential for their winter dens, or hibernacula. These dens must extend below the frost line to allow the snakes to survive the harsh northern winters.
During warmer months, the snakes move into adjacent habitats, such as bluff prairies and forested areas, to hunt and bask. Gravid females often remain close to the den on sun-exposed rock ledges to incubate their developing young. This reliance on specific rocky den sites and nearby foraging habitat limits where they can successfully live.
Current Conservation Status
The population of the Timber Rattlesnake in Minnesota has declined significantly. The state designated the species as Threatened in 1996, which provides the species with full legal protection.
Historically, population decline was accelerated by human persecution, including a state bounty that was in effect until 1989. Habitat loss and fragmentation continue to impact the species, as the bluff prairies they rely on are often degraded or overgrown. Conservation efforts now focus on protecting known den sites and restoring the bluff prairie habitat through prescribed burns and cedar removal.
Identification and Encounter Guidance
Distinguishing a Timber Rattlesnake from harmless species relies on several visual cues beyond the obvious rattle. Non-venomous species like the Western Foxsnake or Milksnake can mimic the rattle sound by vibrating their tails in dry leaves, but they lack the prominent segmented rattle. The rattlesnake also has a heavy, barred body pattern, a triangular head, and unique facial pits.
If you encounter a snake you suspect is a rattlesnake, remain calm and slowly back away. These snakes are generally docile and only strike if they feel directly threatened or provoked. Never attempt to handle, capture, or harm the snake, as this is when most bites occur and the species is legally protected.
If a rattlesnake is found in an area of human activity, the Minnesota Department of Natural Resources has established a Timber Rattlesnake Responder Program. These trained volunteers can be contacted through local non-emergency dispatch numbers to safely relocate the snake. Keeping pets and children away from the area until the snake moves on or is relocated is the safest course of action.