Missouri records
Northern Cottonmouth in Missouri
VenomousAgkistrodon piscivorus

Yes. The Northern Cottonmouth has been recorded in 25 Missouri counties. It is venomous. Heavy body, triangular head, vertical pupils, and a heat-sensing pit between each eye and nostril.
If you are bitten
Copperhead and cottonmouth bites are painful and need medical care but are rarely fatal with prompt treatment (cottonmouth venom is the more potent of the two). Stay calm, keep the limb still, remove tight items, and go to an emergency room. Do not use a tourniquet or cut the wound. Call Poison Control at 1-800-222-1222 or 911 in the US, or your local emergency number. (Source: CDC.)
Missouri counties with Northern Cottonmouth records
25 listedSee the full Northern Cottonmouth profile or all snakes in Missouri.