Sioux County is a county in Nebraska, United States, in the state’s northwest corner where the panhandle meets Wyoming and South Dakota. It had a population of 1,135 at the 2020 census and covers 2,067 square miles (5,353 km2) centred near 42°28′N 103°44′W, making it the sixth-largest county in Nebraska by area and one of the least densely populated in the state.
Harrison is the county seat, and its postal code is 69346. The county has one incorporated town and a handful of small unincorporated communities and former townsites, sits in the Mountain Time Zone, and is part of the Scottsbluff, NE Micropolitan Statistical Area.
Towns & Villages in Sioux County
Sioux County has one incorporated town, Harrison, and a scattering of unincorporated places and ghost towns along its ranch roads and rail grades. “Unincorp.” below means the place has no municipal government; the two ghost towns are historic railroad or post-office sites with no remaining population.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Harrison | Town · seat | 239 | 69346 |
| Agate | Unincorp. | — | 69326 |
| Andrews | Unincorp. | — | — |
| Glen | Unincorp. | — | — |
| Joder | Unincorp. | — | — |
| Story | Unincorp. | — | — |
| Montrose | Ghost town | — | — |
| Orella | Ghost town | — | — |
Two names from older lists are dropped here: “Five Points” and “Spurior Place” have no traceable record as Sioux County place names and are most likely scrape errors or mangled road-junction labels rather than real communities.
ZIP Codes
- 69346 — Harrison (county seat, also serves the surrounding ranch country)
- 69326 — Agate (also serves Agate Fossil Beds National Monument)
The rest of the county’s unincorporated communities and ghost towns have no ZIP code of their own and are served by Harrison’s or Agate’s post office depending on location.
Geography
Sioux County occupies Nebraska’s high, arid northwest corner, a landscape of rolling shortgrass prairie cut by buttes, pine-covered ridges, and the badland-like breaks of the Niobrara and White River drainages. Elevations run higher than almost anywhere else in the state, and ranching rather than row-crop farming dominates the open range. The county holds two federally protected sites: Agate Fossil Beds National Monument, preserving Miocene mammal fossil beds along the Niobrara River, and a portion of the Fort Robinson & Pine Ridge landscape near its eastern edge.
Sioux County borders Dawes County to the northeast, Box Butte County to the southeast, and Scotts Bluff County to the south, all in Nebraska. Its northern border runs along Fall River County, South Dakota, and its western border runs along Niobrara County and Goshen County, Wyoming.
Demographics
Sioux County’s population was 1,135 at the 2020 census, the smallest of any Nebraska panhandle county. Harrison, the only incorporated town, is by far the largest community; Agate is the county’s next-most-recognized place, though it is little more than a rail siding and monument gateway. Density works out to well under one person per square mile, among the lowest in Nebraska. Median household income in the county runs below the Nebraska median of $74,590, reflecting the area’s dependence on ranching rather than higher-wage industries.
Economy & Local Life
Cattle ranching is the county’s economic backbone, on large rangeland operations suited to the dry, high-elevation terrain rather than irrigated cropland. Agate Fossil Beds National Monument, administered by the National Park Service, draws paleontology-focused tourism and supports a small seasonal visitor economy around Harrison and Agate. Harrison itself serves as the county’s only retail, school, and government center for a trade area that stretches across most of the county’s 2,067 square miles.
History
Sioux County was created on February 19, 1877, and formally organized on October 1, 1886, one of the last Nebraska counties to organize as ranching interests slowly settled the panhandle. It is named for the Sioux people, whose historic territory extended across this part of the northern Plains. The county’s fossil-rich terrain later drew federal protection: Agate Fossil Beds, excavated from the early 1900s onward, became a national monument in 1965.
Getting There
Nebraska Highway 29 is the county’s main north–south route through Harrison, connecting to South Dakota at the north end and to U.S. Route 20 to the south.
- Chadron — 55 miles east
- Scottsbluff — 65 miles south
- Lusk, Wyoming — 50 miles west
- Rapid City, South Dakota — 100 miles north
The nearest commercial airport is Western Nebraska Regional Airport in Scottsbluff.
Frequently Asked Questions
Where is Sioux County, Nebraska?
It occupies Nebraska’s extreme northwest corner, bordering Wyoming to the west and South Dakota to the north.
What is the population of Sioux County?
1,135 people, per the 2020 census, the least populous county in the Nebraska panhandle.
How big is Sioux County?
2,067 square miles (5,353 km2) of land, the sixth-largest county in Nebraska by area.
What is the county seat of Sioux County?
Harrison is the county seat.
How many towns are in Sioux County?
One incorporated town, Harrison, plus several unincorporated communities and two ghost towns.
What ZIP codes are in Sioux County?
69346 (Harrison) and 69326 (Agate) are the county’s ZIP codes.
What national monument is in Sioux County?
Agate Fossil Beds National Monument, preserving Miocene-era mammal fossils along the Niobrara River.
More counties in this state: Towns and villages in Nebraska.