Are there cottonmouths in Wisconsin?
Short answer
No
No. There are no open records of the cottonmouth from Wisconsin, and the state is outside its range.
The nearest populations are in Illinois.

Cottonmouths across the US
- Lives here
- Rare records
- Gone
- Not here
How to recognize one
Cottonmouth Agkistrodon piscivorus
- Heavy, dark olive to black body; bands fade with age
- Broad flat head with a dark stripe through the eye
- Swims with the whole body high on the water
Dangerous. A bite is a medical emergency. Most snakes people call water moccasins outside its range are harmless water snakes.
Often mistaken for cottonmouths
- Copperhead vs Cottonmouth Copperhead: medically significant
- Cottonmouth vs Water Snake Water snake: harmless, lives in Wisconsin
- Cottonmouth vs Banded Water Snake Banded water snake: harmless
- Cottonmouth vs Diamondback Water Snake Diamondback water snake: harmless
- Cottonmouth vs Brown Water Snake Brown water snake: harmless
Questions
Are there cottonmouths in Wisconsin?
No. There are no open records of the cottonmouth from Wisconsin, and the state is outside its range.
Where are the nearest cottonmouths to Wisconsin?
In Illinois.
What do cottonmouths look like?
Heavy, dark olive to black body; bands fade with age. Broad flat head with a dark stripe through the eye. Swims with the whole body high on the water.