County Maps US

Pennington County, South Dakota

A county in South Dakota, ranked 2 of 66 by population.

CountyFIPS 46103

Within South Dakota
Pennington County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data.

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Population
116,792
+7,222 (+6.6%) since 2020
Land area
2,777
square miles. A further 0.3% of the total area is water
Population density
42.1
people per square mile, computed rather than published
County seat
Rapid City
Seat of county government.
Established
1875
150 years ago
Largest city
Rapid City city
Population 80,589.

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 Pennington 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 Pennington County, South 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 485 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 Pennington County ranks

Position among the 66 counties of South Dakota, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn South DakotaNationally
Population116,7922nd of 66550th of 3,144
Land area2,777 sq mi3rd of 66187th of 3,144
Population density42.1 per sq mi7th of 661,627th of 3,144
Median household income$74,51724th of 66867th of 3,143

Full data for Pennington County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population116,792Vintage 2025 Population Estimates
Population in 2020109,570Vintage 2025 Population Estimates
2020 estimates base?109,231Vintage 2025 Population Estimates
Land area2,777 sq mi2025 Gazetteer Files
Water area7.7 sq mi2025 Gazetteer Files
Total area2,784 sq mi2025 Gazetteer Files
Population density?42.1 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$74,517American Community Survey 2020-2024 5-Year Estimates
Median home value$302,200American Community Survey 2020-2024 5-Year Estimates
Median age40.1American Community Survey 2020-2024 5-Year Estimates
Households46,370American Community Survey 2020-2024 5-Year Estimates
Housing units51,681American 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
+209
1,339 births, 1,130 deaths
Net migration
+259
More people moved in than moved out.

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

The 7 areas bordering Pennington 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
Meade CountySouth Dakota106 mi30,711
Custer CountySouth Dakota85 mi9,431
Haakon CountySouth Dakota36 mi1,802
Oglala Lakota CountySouth Dakota35 mi13,338
Jackson CountySouth Dakota32 mi2,666
Lawrence CountySouth Dakota30 mi29,459
Weston CountyWyoming20 mi6,840

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

All 66 counties of South Dakota

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

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