List of snakes of South Dakota

Snakes of South Dakota^[1]

Common name	Scientific name	Distribution (within South Dakota)	Description	Photograph
Brown snake	Storeria dekayi	eastern Roberts County (status in question; last formal reported sighting in 1922)	8 - 15 inches in length, greyish-brown to reddish-brown colouration, with light stripe down the center of the back (bordered by parallel row of dark spots), and dark markings under and/or behind each eye
Bullsnake	Pituophis catenifer	All portions of the state west of the Missouri River, all counties adjacent to the east bank of the Missouri River, and across southeastern and central South Dakota	36 - 72 inches in length, yellowish colouration (with brown or black blotches that appear as rings near the tail)
Common garter snake (sometimes called the "red-sided garter snake")	Thamnophis sirtalis	throughout the state	15 - 28 inches in length, bright yellow or orange stripe along middle of the back, yellow or orange stripe along each side, with black spots on red colouration also along both sides
Eastern hognose snake	Heterodon platirhinos	extreme southeastern fringe of the state	20 - 33 inches in length, slightly upturned snout (as compared to the Plains hognose snake), highly variable in colouration (with dark blotches along center, and alternating spots on each side)
Western fox snake	Pantherophis ramspotti	far southeastern South Dakota	36 - 54 inches in length, yellowish to light brown in colouration (with bold blotches)
Lined snake	Tropidoclonion lineatum	far southeastern South Dakota	9 - 15 inches in length, grey or brown in colouration (with three pale stripes; one along the back, and one each along either side)
Western milksnake	Lampropeltis gentilis	the western milksnake is found throughout that portion of the state west of the Missouri River, as well as in counties adjacent to the river's east bank	16 - 28 inches in length, red and orange blotches bordered with black, and separated by yellow or white bands (head is orange with black flecks)
Eastern milksnake	Lampropeltis triangulum syspila	the eastern milksnake subspecies is found in far southeastern South Dakota	16 - 28 inches in length, red and orange blotches bordered with black, and separated by yellow or white bands (with red head & snout)
Plains garter snake	Thamnophis radix	throughout the state	20 - 28 inches in length, bright yellow or orange stripe along middle of the back, with yellow or orange stripe & alternating row of dark spots along each side, with dark head
Plains hognose snake	Heterodon nasicus	throughout the state	15 - 25 inches in length, sharply upturned snout (as compared to the eastern hognose snake), dark blotches along center and sides of body, blackish underside
Prairie rattlesnake	Crotalus viridis	throughout that portion of the state west of the Missouri river, as well as in counties adjacent to the river's east bank	30 - 45 inches in length, South Dakota's only venomous snake (bite is potentially fatal to humans), readily identifiable by rattle segment(s) at the end of the tail, light brown to greenish in colouration, triangular-shaped head with pits located below the midline of each eye & nostril
Racer (sometimes called the "blue racer")	Coluber constrictor foxii	throughout that portion of the state west of the Missouri River, as well as in counties adjacent to the river's east bank	30 - 50 inches in length, adults are blue to greenish in colouration (with a bright yellow belly), while juveniles have an ornate blotched, spotted, and speckled pattern
Redbelly snake ("Black Hills" subspecies)	Storeria occipitomaculata pahasapae	the Black Hills redbelly snake subspecies is found within the Black Hills of South Dakota	8 - 11 inches in length, slender body with grey, brown, or reddish-brown colouration, with a white chin, red belly, light spots on neck, and faint light stripe(s) along the back
Redbelly snake ("northern" subspecies)	Storeria occipitomaculata occipitomaculata	the northern redbelly snake subspecies is found in extreme eastern South Dakota	8 - 11 inches in length, slender body with grey, brown, or reddish-brown colouration, with a white chin, red belly, light spots on neck, and faint light stripe(s) along the back
Ringneck snake	Diadophis punctatus	far southeastern South Dakota	10 - 15 inches in length, dark (black or grey) upper body, a yellow or orange belly (with black spots), and a bright yellow or yellow-orange ring around the neck
Smooth green snake	Liochlorophis vernalis	non-contiguous regions of far northeastern and far southeastern South Dakota, plus a third pocket in the Black Hills	14 - 20 inches in length, small and slender, with uniformly green upper body, head, and tail (and a whitish belly)
Wandering garter snake	Thamnophis elegans vagrans[2]	the Black Hills	18 - 30 inches in length, dull brown to greenish in colouration, yellow or orange mid-dorsal stripe on each side, a brown head (with yellow spots) and black bars on the lips
Water snake (sometimes called the "northern water snake")	Nerodia sipedon	southern riverine and wetland areas of Bon Homme County (near Springfield)	24 - 42 inches in length, dark brown to grey in colouration, dark upper bands on front part of body, alternating dark blotches or crossbands on the rear portion of the upper body (juveniles are lighter in color)