Snakes in South Dakota
South Dakota has 16 snake species on record, each with at least 10 GBIF records in the state, and 3,185 licensed records in all. The most recorded are the prairie rattlesnake, the western terrestrial garter snake and the plains garter snake. One of them is venomous.
Rattlesnakes in South Dakota
One species of this group is listed for South Dakota: the prairie rattlesnake, with 970 records (30% of the state's snake records).
Observation records of the prairie rattlesnake in South Dakota run mostly May through October, peaking in June; most licensed records come from Hughes County, Stanley County and Dewey County.
Garter snakes and ribbon snakes in South Dakota
Garter snakes and ribbon snakes dominate the snake record of South Dakota: three species and 43% of all records. The most recorded is the western terrestrial garter snake (590), ahead of the plains garter snake (514).
Most licensed records of the western terrestrial garter snake in South Dakota come from Pennington County, Butte County and Custer County. Observation records of the plains garter snake in South Dakota run mostly April through October, peaking in June; most licensed records come from Clay County, Brookings County and Union County. Most licensed records of the common garter snake in South Dakota come from Bon Homme County, Clay County and Roberts County.
Rat snakes and corn snakes in South Dakota
Rat snakes and corn snakes are a small part of the snake record here: two species with 3% of records between them. The most recorded is the western foxsnake (64), ahead of the eastern fox snake (31).
Most licensed records of the western foxsnake in South Dakota come from Clay County, Union County and Minnehaha County. Most licensed records of the eastern fox snake in South Dakota come from Clay County, Union County and Bon Homme County.
Kingsnakes and milksnakes in South Dakota
Kingsnakes and milksnakes are a small part of the snake record here: two species with 1% of records between them. The most recorded is the eastern milksnake (31), ahead of the central plains milksnake (4).
Most licensed records of the eastern milksnake in South Dakota come from Custer County, Clay County and Hughes County.
Racers, whipsnakes and indigo snakes in South Dakota
One species of this group is listed for South Dakota: the eastern racer, with 135 records (4% of the state's snake records).
Most licensed records of the eastern racer in South Dakota come from Custer County, Jackson County and Clay County.
Gopher snakes, bullsnakes and pine snakes in South Dakota
One species of this group is listed for South Dakota: the gopher snake, with 185 records (6% of the state's snake records).
Observation records of the gopher snake in South Dakota run mostly May through September, peaking in May; most licensed records come from Pennington County, Jackson County and Custer County.
Hognose snakes in South Dakota
Hognose snakes are a small part of the snake record here: two species with 2% of records between them. The most recorded is the plains hog-nosed snake (40), ahead of the eastern hog-nosed snake (10).
Most licensed records of the plains hog-nosed snake in South Dakota come from Harding County, Jackson County and Charles Mix County.
Green snakes in South Dakota
One species of this group is listed for South Dakota: the smooth green snake, with 124 records (4% of the state's snake records).
Most licensed records of the smooth green snake in South Dakota come from Lawrence County, Custer County and Pennington County.
Small woodland and burrowing snakes in South Dakota
Small woodland and burrowing snakes: three species are listed for South Dakota, with 203 records (6% of the state's snake records). The most recorded is the red-bellied snake (99), ahead of the ring-necked snake (84).
Most licensed records of the red-bellied snake in South Dakota come from Lincoln County, Hutchinson County and Custer County. Most licensed records of the ring-necked snake in South Dakota come from Minnehaha County, Bon Homme County and Union County.
Where in South Dakota are snakes recorded most?
Pennington County leads with 414 records (13%), followed by Hughes County and Butte County; the top five counties hold 46% of the total. 66 of South Dakota's 66 counties have at least one licensed snake record.
| # | County | Records | Share |
|---|---|---|---|
| 1 | Pennington County | 414 | 13.0% |
| 2 | Hughes County | 403 | 12.7% |
| 3 | Butte County | 241 | 7.6% |
| 4 | Custer County | 215 | 6.8% |
| 5 | Clay County | 195 | 6.1% |
| 6 | Stanley County | 125 | 3.9% |
| 7 | Dewey County | 110 | 3.5% |
| 8 | Lawrence County | 110 | 3.5% |
| 9 | Union County | 108 | 3.4% |
| 10 | Gregory County | 107 | 3.4% |
| 11 | Jackson County | 97 | 3.0% |
| 12 | Bon Homme County | 88 | 2.8% |
When do snakes come out in South Dakota?
Observation records of snakes in South Dakota run mostly May through October, peaking in June with 27% of them. December through February together hold under 2% of the records, so snakes in South Dakota are rarely recorded in winter. The sharpest rise comes from April to May.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1% | 0% | 0% | 7% | 17% | 27% | 19% | 10% | 8% | 9% | 2% | 0% |
Snakes: South Dakota compared with its neighbors
South Dakota ranks 33rd of 50 states by the number of snake species listed, level with Oregon and Wisconsin; Texas leads with 86 species.
Of the six states bordering South Dakota, Nebraska and Iowa list more snake species (South Dakota: 16 species; Nebraska 31, Iowa 22, Minnesota 15, Wyoming 11, Montana 9, North Dakota 8).
What snakes are in South Dakota? All 16 species
Ranked by licensed records in South Dakota. Species with a profile page are linked.
| # | Species | Family | Records | Share |
|---|---|---|---|---|
| 1 | Prairie rattlesnake venomous Crotalus viridis | Viperidae | 970 | 30.5% |
| 2 | Western terrestrial garter snake Thamnophis elegans | Colubridae | 590 | 18.5% |
| 3 | Plains garter snake Thamnophis radix | Colubridae | 514 | 16.1% |
| 4 | Common garter snake Thamnophis sirtalis | Colubridae | 271 | 8.5% |
| 5 | Gopher snake Pituophis catenifer | Colubridae | 185 | 5.8% |
| 6 | Eastern racer Coluber constrictor | Colubridae | 135 | 4.2% |
| 7 | Smooth green snake Opheodrys vernalis | Colubridae | 124 | 3.9% |
| 8 | Red-bellied snake Storeria occipitomaculata | Colubridae | 99 | 3.1% |
| 9 | Ring-necked snake Diadophis punctatus | Colubridae | 84 | 2.6% |
| 10 | Western foxsnake Pantherophis ramspotti | Colubridae | 64 | 2.0% |
| 11 | Plains hog-nosed snake Heterodon nasicus | Colubridae | 40 | 1.3% |
| 12 | Eastern fox snake Pantherophis vulpinus | Colubridae | 31 | 1.0% |
| 13 | Eastern milksnake Lampropeltis triangulum | Colubridae | 31 | 1.0% |
| 14 | Lined snake Tropidoclonion lineatum | Colubridae | 20 | 0.6% |
| 15 | Eastern hog-nosed snake Heterodon platirhinos | Colubridae | 10 | 0.3% |
| 16 | Central plains milksnake Lampropeltis gentilis | Colubridae | 4 | 0.1% |
Also recorded in South Dakota, fewer than 10 times
Beyond the main list, two snake species are known from South Dakota by only 3 to 9 records each. Some are genuine rarities at the edge of their range; others may be strays, released pets or old misidentifications, so treat them as unconfirmed.
Related pages
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.