Venomous snakes in Wisconsin
Venomous snakes living in Wisconsin
2species, plus 2 with rare records
Timber rattlesnake, Eastern massasauga. A bite from the timber rattlesnake is a medical emergency.
How to recognize them
Timber rattlesnakeDangerous126 records, 7 counties
Eastern massasaugaMedically significant87 records, 7 counties
Timber rattlesnake Crotalus horridus
- Dark V- or chevron-shaped bands across the back
- Black tail ending in a rattle
- Yellow, tan or dark phases; some are almost black
Eastern massasauga Sistrurus catenatus
- Gray or brown with large dark blotches down the back
- Small rattle
- Nine large plates on top of the head
Every venomous snake species known from the US is on this site.
Counties with records
- None recorded
- 1 species
- 2
- 3 to 4
- 5 or more
Active months
Rare records
- Rare records Western diamondback rattlesnake 3 open records
- Rare records Copperhead 1 open record, latest 1954
Harmless snakes people mistake for them
Water snakeHarmlessHarmless
Northern water snakeHarmlessHarmless
Eastern hognose snakeHarmlessHarmless
Milk snakeHarmlessHarmless
Gopher snakeHarmlessHarmless
Quick answers
- Lives here Are there rattlesnakes in Wisconsin?
- Rare records Are there copperheads in Wisconsin?
- Not here Are there cottonmouths in Wisconsin?
Questions
How many venomous snakes are in Wisconsin?
2 species live in the state: Timber rattlesnake and Eastern massasauga.
Which venomous snakes in Wisconsin are dangerous?
Timber rattlesnake and Eastern massasauga: a bite is a medical emergency.
When are venomous snakes most active in Wisconsin?
Most open records fall in May, August.
More for Wisconsin
- All venomous animals in Wisconsin
- Venomous spiders in Wisconsin
- Scorpions in Wisconsin
- Centipedes in Wisconsin