Sioux County area

Sioux County, Nebraska covers 2,067.4 square miles: 2,066.7 square miles of land and 0.642 square miles of water. Its county seat is Harrison. An estimated 1,188 people lived there in 2025.

Official Census measurements · GEOID 311652026 Gazetteer · retrieved September 27, 2026
Land area2,066.7 mi²
Water area0.642 mi²
Population (2025)1,188
People per mi²0.57

County outline

Generalized outline of Sioux County, Nebraska
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Sioux County is located

Sioux County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 100% of Sioux County’s measured area and water for 0%. Its combined area converts to 5,354.5 square kilometers or approximately 1,323,114 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land2,066.7235,352.7881,322,702.7
Water0.6421.663410.9
Total2,067.3655,354.4511,323,113.6

How Sioux County compares

By original Census land area, Sioux County ranks #6 of 93 in Nebraska and #276 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 3.593 times the Nebraska county-equivalent median of 575.2 square miles. It accounts for 2.7% of the combined county land area in the state.

See the complete Nebraska ranking · What counts as a county equivalent?

Population and density of Sioux County

The Census Bureau estimates that 1,188 people lived in Sioux County on July 1, 2025. That ranks #3,176 of 3,222 county equivalents nationally and #81 of 93 in Nebraska. Since the April 1, 2020 estimates base of 1,137, the population has grown by 51 (+4.5%), compared with +2.9% for Nebraska as a whole.

With 2,066.7 square miles of land, that is 0.57 people per square mile (0.22 per km²), placing Sioux County #3,189 nationally for density and #91 in Nebraska. The median county equivalent has 47 people per square mile; the Nebraska median is 8. Put another way, there are about 1,113 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate1,1461,1551,1661,2001,2051,188
Change—+9+11+34+5−17

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Sioux County

1 incorporated place lies at least partly in Sioux County. Together they are home to 247 people (20.8%); the other 941 (79.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Harrison village, with 247 residents in the county.

Metropolitan area

Sioux County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.

ZIP codes

8 ZIP Code Tabulation Areas have land in Sioux County; 5 of them have most of their land inside the county, and the others mainly cover neighboring areas.

5773569339693466934869354693576935869361

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Sioux County

Sioux County shares a land border with 6 county equivalents, including 3 in Wyoming and South Dakota. It has more land than 4 of them. The largest neighbor is Niobrara County (2,626 mi²) and the smallest is Scotts Bluff County (739.6 mi²). Together with its neighbors, Sioux County forms a block of 11,869.5 mi² of land, of which it holds 17.4%.

Map of Sioux County and the 6 county equivalents that border it Goshen County, Wyoming: 2,225.6 mi² landDawes County, Nebraska: 1,396.4 mi² landScotts Bluff County, Nebraska: 739.6 mi² landBox Butte County, Nebraska: 1,075.2 mi² landFall River County, South Dakota: 1,739.9 mi² landNiobrara County, Wyoming: 2,626 mi² land
Sioux County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. SiouxCompare
Niobrara CountyWyoming2,6261.3× largerCompare
Goshen CountyWyoming2,225.61.1× largerCompare
Fall River CountySouth Dakota1,739.91.2× smallerCompare
Dawes County1,396.41.5× smallerCompare
Box Butte County1,075.21.9× smallerCompare
Scotts Bluff County739.62.8× smallerCompare

How big is Sioux County compared with U.S. states?

Sioux County has more land than 2 of the 50 states. It is about 1.1 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 2.3 times as much land (4,842.5 mi²). Nebraska’s county land could hold about 37 areas the size of Sioux County.

Land area: Sioux County and the closest-sized states
Delaware1,948.6 mi²
Sioux County2,066.7 mi²
Connecticut4,842.5 mi²

Another way to picture it: the same land area would fill a square about 45.5 miles (73.2 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Sioux County?

Sioux County has more land than 2,946 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Sioux County2,066.7 mi²
Nebraska median575.2 mi²
National median604.5 mi²

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Sioux County at #307 nationally by total area, 31 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 0%, compared with a national county-equivalent median of 1.2% — 1.1 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Sioux County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#275Oxford County, Maine2,077Compare
#276Sioux County, Nebraska2,066.7This county
#277Carbon County, Montana2,047.9Compare

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.

Representative coordinates

The Census internal point is 42.470651, -103.732168. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.

Source and precision

U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 5,352,788,397 m²; AWATER: 1,662,499 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Sioux County?

Sioux County, Nebraska has 2,066.7 square miles (5,352.8 km²) of land and 0.642 square miles of water, for a total area of 2,067.4 square miles. It ranks #276 of 3,222 U.S. county equivalents by land area.

Is Sioux County the largest county in Nebraska?

No. Sioux County ranks #6 of 93 in Nebraska by land area. The largest is Cherry County, with 5,960.1 square miles of land.

What counties border Sioux County?

Sioux County shares a land border with Goshen County, Wyoming, Dawes County, Scotts Bluff County, Box Butte County, Fall River County, South Dakota, and Niobrara County, Wyoming.

What is the population of Sioux County?

The Census Bureau estimates Sioux County had 1,188 residents on July 1, 2025, ranking #3,176 of 3,222 county equivalents. That is 0.57 people per square mile of land.

What is the county seat of Sioux County?

The county seat of Sioux County is Harrison.

Is Sioux County part of a metropolitan area?

No. Sioux County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Sioux County?

8 ZIP Code Tabulation Areas have land in Sioux County, and 5 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Sioux County compare with U.S. states?

It has more land than 2 of the 50 states, including Delaware (1,948.6 square miles of land).

How many acres of land are in Sioux County?

The land measurement converts to approximately 1,322,703 acres. Including water, total area is approximately 1,323,114 acres. One square mile equals 640 acres.

Why might another source show a different area?

Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.

Can this establish a property boundary?

No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.

Cite this county

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