South Dakota records
Common Watersnake in South Dakota
HarmlessNerodia sipedon

Yes. The Common Watersnake has been recorded in 3 South Dakota counties. It is non-venomous (harmless). Heavy banded or blotched body, round pupils, and a narrow head — unlike the cottonmouth's broad, blocky head.
South Dakota counties with Common Watersnake records
3 listedSee the full Common Watersnake profile or all snakes in South Dakota.