Corson County is a county in South Dakota, United States, formed almost entirely of the Standing Rock Indian Reservation along the Missouri River’s western bank. It had a population of 3,902 at the 2020 census and covers 2,530 square miles (6,600 km2), centred near 45°43′N 101°11′W.
McIntosh is the county seat, and its postal code is 57641. The county holds two cities, one town, four census-designated places, and a dozen smaller unincorporated communities. It observes Mountain Time, the only South Dakota county entirely on Mountain rather than Central Time east of the Missouri River line.
Towns & Villages in Corson County
Corson County has 18 named places on record, split between two incorporated cities, one incorporated town, four census-designated places, and eleven unincorporated communities too small for their own census count.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| McLaughlin | City | — | 57642 |
| McIntosh | City · seat | — | 57641 |
| Morristown | Town | — | 57645 |
| Bullhead | CDP | — | 57621 |
| Kenel | CDP | — | — |
| Little Eagle | CDP | — | 57639 |
| Wakpala | CDP | — | 57658 |
| Athboy | Unincorp. | — | — |
| Black Horse | Unincorp. | — | — |
| Jeffrey | Unincorp. | — | — |
| Keldron | Unincorp. | — | 57634 |
| Mahto | Unincorp. | — | — |
| Maple Leaf | Unincorp. | — | — |
| Miscol | Unincorp. | — | — |
| Snake Creek | Unincorp. | — | — |
| Thunder Hawk | Unincorp. | — | — |
| Trail City | Unincorp. | — | — |
| Walker | Unincorp. | — | 57659 |
| Watauga | Unincorp. | — | — |
ZIP Codes
- 57641 — McIntosh (county seat post office)
- 57642 — McLaughlin
- 57645 — Morristown
- 57621 — Bullhead
- 57658 — Wakpala
- 57639 — Little Eagle
- 57634 — Keldron
- 57659 — Walker
Kenel and the smaller unincorporated communities have no dedicated post office and use a nearby town’s ZIP code.
Geography
The Missouri River forms the county’s eastern boundary, and the Grand River crosses the central part of the county on its way to join it. The land is semi-arid rolling prairie, rising to about 2,582 feet near the northwest corner; the Standing Rock Indian Reservation, shared with Sioux, Dewey and Ziebach counties, covers the entire county.
Corson County borders Sioux County, North Dakota to the north, Campbell County to the east, Walworth County to the southeast, Dewey County and Ziebach County to the south, Perkins County to the west, and Adams County, North Dakota to the northwest. Campbell County borders it directly east.
Demographics
Corson County had 3,902 residents at the 2020 census, the majority Native American, reflecting the Standing Rock Sioux Reservation that covers the whole county. McLaughlin is the largest community, followed by the county seat, McIntosh. Median household income in the county runs well below the South Dakota median of $71,810, consistent with reservation-county income patterns statewide. Population density is roughly 1.6 people per square mile, among the lowest in the state.
Economy & Local Life
Tribal government and administration, ranching, and public services are the county’s main employers; the Standing Rock Sioux Tribe’s government functions are centered at Fort Yates just across the North Dakota line. Cattle ranching dominates the rural economy on the reservation’s open range. Corson County has produced Triceratops fossils from the Hell Creek Formation, some of which are now in museum collections.
History
Corson County was organized in 1909 and named for Dighton Corson, a Maine-born lawyer who moved to the Black Hills in 1876 and began practicing law in Deadwood the following year. The county has been part of the Standing Rock Indian Reservation since the reservation’s creation, and its towns grew up along the railroad and river landings that once served the northern reservation.
Getting There
U.S. Route 12 crosses the northern part of the county through McLaughlin and McIntosh; state highways connect the smaller communities south toward the Grand and Moreau river valleys.
- Mobridge, South Dakota — 30 miles east
- Bismarck, North Dakota — 90 miles north
- Lemmon, South Dakota — 45 miles west
The nearest commercial airport is Bismarck Airport in North Dakota.
Frequently Asked Questions
Where is Corson County?
It is in the north-central part of South Dakota, on the Missouri River along the North Dakota border.
What is the population of Corson County?
3,902 people at the 2020 census.
How big is Corson County?
2,530 square miles (6,600 km2), of which 60 square miles are water.
What is the county seat of Corson County?
McIntosh is the county seat.
How many towns are in Corson County?
Two cities, one town, four census-designated places, and about a dozen unincorporated communities.
What ZIP codes are in Corson County?
McIntosh (57641), McLaughlin (57642), Morristown (57645), Bullhead (57621), Wakpala (57658), Little Eagle (57639), Keldron (57634), and Walker (57659).
What Indian reservation covers Corson County?
The Standing Rock Indian Reservation covers the entire county, shared with Sioux, Dewey, and Ziebach counties.
More counties in this state: Towns and villages in South Dakota.