Northern Cottonmouth
Agkistrodon piscivorus
Size
30–42 in
Status
Endangered
Venomous
Yes
Region
SW IN (historic)
A venomous, semi-aquatic pit viper that is now likely gone from Indiana. The last confirmed individuals were found in Dubois County in the 1980s.
Identification
A thick-bodied dark snake with a broad, blocky head and vertical pupils. When threatened it gapes to show the white "cotton" lining of its mouth. Adults are dark olive to black with faint crossbands; young are paler with a yellow-tipped tail.
Habitat & Diet
Associated with swamps, sloughs, and slow southern wetlands. It feeds on fish, amphibians, and other prey in and around water. Unlike harmless water snakes, it often swims with its body riding high on the surface.
Conservation in Indiana
State Endangered and most likely extirpated from Indiana, with no confirmed sightings in decades. Report any suspected sighting to state wildlife authorities — nearly all "cottonmouths" in Indiana are actually harmless watersnakes.
Similar Species & Taxonomy
Frequently confused with Indiana's harmless watersnakes, but the Cottonmouth has a heat-sensing facial pit, vertical pupils, a blocky head, and a white mouth lining it gapes when threatened, and it swims with the body riding high on the water. A pit viper (family Viperidae). A 2015 genetic study split the cottonmouths into the Northern Cottonmouth (Agkistrodon piscivorus) and the Florida Cottonmouth (A. conanti).
United States Range Map Distribution
Distribution in Indiana
