Snakes in Wisconsin

Wisconsin has about 24 snake species, of which 14-15 of them occur rarely, enlisted as endangered, of special concern, or threatened. The reasons for depletion in their numbers include human intervention and habitat loss. The two venomous snakes present here in small numbers – timber rattlesnake and the eastern massasauga live in the southwestern part, with the latter being endangered and federally threatened

Of the non-venomous snakes, the smooth green snake, also known as the grass snake, is found throughout Wisconsin, dwelling along prairies, grasslands, and forest edges. Another harmless snake, the Butler’s garter snake, was enlisted as a protected species in 1997. However, with an increase in its population, proposals have come from several quarters to remove it from the endangered and threatened species list.

Snakes in Wisconsin (WI)
GroupsVenomousNon-venomous
RattlesnakesTimber Rattlesnake
Eastern Massasauga
Water SnakesCommon Watersnake
KingsnakesMilksnake Eastern Milksnake
Garter SnakesButler’s Garter Snake
Common Garter Snake
Plains Garter Snake
Eastern Ribbon Snake
Western Ribbon Snake
Hognose SnakesEastern Hog-nosed Snake
Whip SnakesStriped Whip Snake
DiadophisNorthern Ring-necked Snake Prairie Ring-necked Snake
ColuberEastern Racer
CarphophisWestern Worm Snake
OpheodrysSmooth Greensnake

Pantherophis
Black Rat Snake
Gray Rat Snake
Eastern Fox Snake
PituophisGopher Snake
Pine Snake
StoreriaDeKay’s Brownsnake
Redbelly Snake
TropidoclonionLined Snake
ReginaQueen Snake

Snakes by Colors and Patterns

Brown Snakes: DeKay’s Brownsnake, Common Garter Snake, Butler’s Garter Snake, Eastern Ribbonsnake 

Black Snakes: Black Rat Snake, Eastern Racer

Snakes by Regions

Snakes in Northern Wisconsin: Smooth Greensnake

Snakes in Southern Wisconsin: Timber Rattlesnake, Prairie Ring-necked Snake, Black Rat Snake

Snakes in Central Wisconsin: Smooth Greensnake

Quick Information

Biggest Snake: Gopher Snake

Deadliest Snake: Timber Rattlesnake