Venomous snakes and spiders in South Dakota

The only venomous snake on the South Dakota list is the prairie rattlesnake, with 970 licensed records, 30% of all snake records in the state.

One widow species (Western black widow: 3 records) is on the South Dakota list. There is no recluse spider on the South Dakota list: no recluse species reaches 10 records in the state. Widow bites cause muscle pain and cramps; recluse bites can cause a slow-healing wound. Both are rare and seldom fatal.

These eight account for 63% of all licensed snake records in South Dakota; the most recorded, the western terrestrial garter snake, alone for 19%.

These eight account for 40% of all licensed spider records in South Dakota; the most recorded, the banded garden spider, alone for 12%.

Observation records of venomous snakes in South Dakota run mostly May through October, peaking in June with 22% of them. December through February together hold under 2% of the records, so venomous snakes in South Dakota are rarely recorded in winter.

Observation records of spiders in South Dakota run mostly May through October, peaking in August with 29% of them. December through February together hold under 2% of the records, so spiders in South Dakota are rarely recorded in winter.

Hughes County has the most records of venomous snakes in South Dakota, 381, most of them of the prairie rattlesnake. Stanley County and Dewey County follow.

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.

South Dakota county with its own page: Pennington County.

Yes. South Dakota has one venomous snake species on its list, the kind people usually call poisonous: prairie rattlesnake. Strictly, snakes are venomous (they inject venom), not poisonous (harmful to eat or touch).

Yes. One species is on the South Dakota list: the prairie rattlesnake, with 970 licensed records. Most licensed records of the prairie rattlesnake come from Hughes County, Stanley County and Dewey County.

No. GBIF holds no copperhead record for South Dakota under any license.

No. GBIF holds no cottonmouth record for South Dakota under any license.

No. GBIF holds no coral snake record for South Dakota under any license.

South Dakota has 970 licensed records of the prairie rattlesnake, which ranks the state 2nd of the 14 states where it reaches our threshold. Its observation records in South Dakota run mostly May through October, peaking in June; most licensed records come from Hughes County, Stanley County and Dewey County. Range in other states and photos: Prairie rattlesnake profile.

Many snakes and spiders taken for venomous ones are harmless species with a similar look. These are the usual confusions, with each species' licensed records in South Dakota.

No copperheads reach the South Dakota list, and GBIF holds no copperhead record for South Dakota under any license, so a snake taken for one here is most likely a harmless lookalike. Those recorded in the state: eastern milksnake (31), eastern hog-nosed snake (10) and central plains milksnake (4).

Rattlesnakes: 970 licensed records in South Dakota. Harmless species often taken for them are also on the state list: gopher snake (185), western foxsnake (64), plains hog-nosed snake (40), eastern fox snake (31) and eastern hog-nosed snake (10). Together they have 330 licensed records, and here the venomous species are the more recorded side, 2.9 to 1.

No coral snakes reach the South Dakota list, and GBIF holds no coral snake record for South Dakota under any license, so a snake taken for one here is most likely a harmless lookalike. Those recorded in the state: eastern milksnake (31) and central plains milksnake (4).

Widow spiders: 3 licensed records in South Dakota. Harmless species often taken for them are also on the state list: triangulate bud spider (2). It has 2 licensed records, and here the venomous species are the more recorded side, 1.5 to 1.

Recluse spiders are not on the South Dakota list, but they are recorded in South Dakota once (records of any license: brown recluse 1): treat any spider like this as venomous until identified. Harmless species often taken for them in the state: longbodied cellar spider (3).

By count of venomous snake species, South Dakota ranks 37th of 50 states, level with 8 other states. Nationally, Arizona leads with 14 species; five list none.

Of the six states bordering South Dakota, Nebraska, Iowa and Wyoming list more venomous snake species; Minnesota, Montana and North Dakota list as many (South Dakota: 1 species; Nebraska 4, Iowa 3, Wyoming 2, Minnesota 1, Montana 1, North Dakota 1).

Venomous snakes listed next door but not in South Dakota: the timber rattlesnake (Iowa, Minnesota and Nebraska); the eastern copperhead (Nebraska); the eastern massasauga (Iowa); the western massasauga (Nebraska); the western rattlesnake (Wyoming). The most widely shared is the prairie rattlesnake, listed in five of the six bordering states.

Yes. One widow species is on the South Dakota list: the western black widow (3 records).

Not on our list: GBIF holds 1 brown recluse record of any license in South Dakota (brown recluse 1), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Treat any spider that looks like a recluse as venomous.

South Dakota has 3 licensed records of the western black widow, which ranks the state 17th of the 18 states where it reaches our threshold. Range in other states and photos: Western black widow profile.

Not on our list: GBIF holds 1 scorpion record of any license in South Dakota (northern scorpion 1), fewer than 10 of any one species; such records can be genuine rarities, strays, transported animals or misidentifications. Every scorpion has venom; only the Arizona bark scorpion's sting is medically significant, and it is not on the South Dakota list.