County Maps US

Sioux County, North Dakota

A county in North Dakota, ranked 30 of 53 by population.

CountyFIPS 38085

Within North Dakota
Sioux County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Fort Yates, the county seat, located via the 2025 Census Gazetteer.

Download SVGFull North Dakota map downloads

Population
3,667
-209 (-5.4%) since 2020
Land area
1,094
square miles. A further 3.0% of the total area is water
Population density
3.4
people per square mile, computed rather than published
County seat
Fort Yates
Seat of county government.
Established
1915
110 years ago
Largest city
Fort Yates city
Population 167.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Sioux County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Sioux County, North Dakota from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 800 by 422 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Sioux County ranks

Position among the 53 counties of North Dakota, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn North DakotaNationally
Population3,66730th of 532,911th of 3,144
Land area1,094 sq mi34th of 53583rd of 3,144
Population density3.4 per sq mi29th of 532,876th of 3,144
Median household income$42,08353rd of 533,025th of 3,143

Full data for Sioux County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population3,667Vintage 2025 Population Estimates
Population in 20203,876Vintage 2025 Population Estimates
2020 estimates base?3,893Vintage 2025 Population Estimates
Land area1,094 sq mi2025 Gazetteer Files
Water area34.2 sq mi2025 Gazetteer Files
Total area1,128 sq mi2025 Gazetteer Files
Population density?3.4 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$42,083American Community Survey 2020-2024 5-Year Estimates
Median home value$85,400American Community Survey 2020-2024 5-Year Estimates
Median age28.2American Community Survey 2020-2024 5-Year Estimates
Households1,112American Community Survey 2020-2024 5-Year Estimates
Housing units1,280American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
+5
50 births, 45 deaths
Net migration
-55
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 5 areas bordering Sioux County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Grant CountyNorth Dakota132 mi2,206
Corson CountySouth Dakota72 mi3,781
Morton CountyNorth Dakota44 mi34,601
Emmons CountyNorth Dakota38 mi3,215
Adams CountyNorth Dakota7.5 mi2,275

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 53 counties of North Dakota

Open the interactive North Dakota county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.