Ziebach County is a county in South Dakota, United States, lying entirely inside the Cheyenne River and Standing Rock Sioux reservations along the Cheyenne and Moreau rivers. It had a population of 2,413 at the 2020 census, making it one of the least populous counties in the state, and covers 1,961 square miles (5,080 km2) of land centred near 44°59′N 101°40′W.
Dupree is the county seat, and its postal code is 57623. The county has one incorporated town, two census-designated places, and several unincorporated communities scattered across open ranchland. Ziebach runs on Mountain Time and, alphabetically, is the last county in the United States.
Towns & Villages in Ziebach County
Most of Ziebach County’s population lives in Dupree or in small reservation communities along Highway 212 and the Moreau River. The table below lists every named place with a Census Bureau designation or long-standing local recognition.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Dupree | Town · seat | 494 | 57623 |
| Cherry Creek | CDP | 282 | 57622 |
| Bridger | CDP | 48 | 57748 |
| Red Scaffold | Unincorp. | — | — |
| Thunder Butte | Unincorp. | — | — |
| Glad Valley | Unincorp. | — | — |
| Red Elm | Unincorp. | — | — |
| Iron Lightning | Unincorp. | — | — |
| Chase | Unincorp. | — | — |
| Allison Crossing | Unincorp. | — | — |
ZIP Codes
- 57623 — Dupree (also serves Red Scaffold, Thunder Butte and Chase)
- 57622 — Cherry Creek
- 57748 — Bridger (shared with Howes in neighboring Meade County)
Glad Valley, Red Elm, Iron Lightning and Allison Crossing have no dedicated post office and are served through Dupree or Cherry Creek routes.
Geography
Ziebach County sits on the Missouri Plateau between the Cheyenne and Moreau rivers, a landscape of grassland buttes, breaks and shelterbelts with almost no tree cover outside the river bottoms. Thunder Butte, at 2,733 feet, is the county’s high point and a landmark visible for miles across the surrounding ranchland. Nearly the entire county lies within the Cheyenne River Sioux or Standing Rock Sioux reservations, and land ownership is a mix of tribal trust land, individual allotments and non-Native ranches.
Ziebach County borders seven counties: Corson County to the north, Dewey County to the east, Stanley County to the southeast, Haakon County to the south, Pennington County to the southwest, Meade County to the west, and Perkins County to the northwest.
Demographics
The 2020 census counted 2,413 residents, and the most recent Census Bureau estimate puts the county at roughly 2,389, a slight decline typical of the rural Cheyenne River region. Dupree and Cherry Creek are the two largest communities. South Dakota’s median household income was $71,810 in the 2023 American Community Survey; Ziebach County’s figure runs well below that mark, and the county is consistently ranked among the poorest in the country by per-capita income. Population density is under two people per square mile, among the lowest of any county in the state.
Economy & Local Life
Cattle ranching and hay production dominate the local economy, alongside tribal government, the Cheyenne River Sioux Tribe’s administrative offices, the Dupree school district and the Indian Health Service clinic in Eagle Butte just across the Dewey County line. Many residents work for the tribe or the county, and small general stores in Dupree and Cherry Creek serve as the main retail points for dozens of miles. The Ziebach County Fair, held each summer in Dupree, is the county’s biggest community gathering, drawing ranch families and rodeo competitors from across the reservation.
History
Ziebach County was created and organized on February 1, 1911, carved from a larger unorganized territory west of the Missouri River. It is named for Frank M. Ziebach, a pioneer newspaperman and territorial legislator who helped organize Dakota Territory’s government in the 1860s. The county has long been closely tied to Sioux governance: much of its land was folded into the Cheyenne River and Standing Rock reservations under 19th-century treaties, and tribal jurisdiction continues to shape land use and local services today.
Getting There
U.S. Route 212 crosses the county east–west through Dupree, connecting to South Dakota Highways 20, 34, 63 and 65 for the outlying communities.
- Eagle Butte — 24 miles east
- Faith — 34 miles west
- Timber Lake — 45 miles northeast
- Pierre — 95 miles southeast
The nearest commercial airport is Pierre Regional Airport. There is no Amtrak service in this part of South Dakota; the nearest station is in Havre, Montana, over 300 miles away.
Frequently Asked Questions
What is the Dupree postcode?
57623.
What county is Dupree, South Dakota in?
Dupree is the county seat of Ziebach County.
How many people live in Ziebach County?
2,413 at the 2020 census, with a recent estimate near 2,389.
What is Ziebach County’s land area?
1,961 square miles (5,080 km2) of land, plus 9.3 square miles (24 km2) of water.
Is Ziebach County on a reservation?
Yes. It lies almost entirely within the Cheyenne River and Standing Rock Sioux reservations.
What time zone is Ziebach County in?
Mountain Time.
Why is Ziebach County called the last county in the alphabet?
Among all counties and county equivalents in the United States, “Ziebach” sorts last alphabetically.
More counties in this state: Towns and villages in South Dakota.