Know the dangerous ones
Venomous snakes in Cook County, Illinois
2 venomous snake species have verified records in Cook County. Learn to recognize each one, and know what to do if you are bitten.
Field entries
Sistrurus catenatus Eastern MassasaugaVenomousSistrurus catenatus
How to identify
Stout, dark-blotched body, nine large scales on the crown, and a small rattle.
Rarely seenFull profile →
Agkistrodon piscivorus Northern CottonmouthVenomousAgkistrodon piscivorus
How to identify
Heavy body, triangular head, vertical pupils, and a heat-sensing pit between each eye and nostril.
Rarely seenFull profile →
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