Illinois
Snakes in Mercer County
7 species have been documented here, 1 of them venomous.
Venomous snakes in Mercer County
Full guide & what to do if bitten →
Eastern MassasaugaSistrurus catenatusVenomousStout, dark-blotched body, nine large scales on the crown, and a small rattle.
Every snake recorded in Mercer County
Common Garter Snake
Thamnophis sirtalis
Harmless
Common Watersnake
Nerodia sipedon
Harmless
North American Racer
Coluber constrictor
Harmless
Eastern Foxsnake
Pantherophis vulpinus
Harmless
DeKay's Brownsnake
Storeria dekayi
Harmless
Eastern Milksnake
Lampropeltis triangulum
Harmless
Eastern Massasauga
Sistrurus catenatus
Venomous
Compiled from verified GBIF & iNaturalist observations. Informational only.