County Maps US

Adams County, Iowa

The least populous of Iowa's 99 counties.

CountyFIPS 19003

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

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Population
3,617
-93 (-2.5%) since 2020
Land area
423.4
square miles. A further 0.5% of the total area is water
Population density
8.5
people per square mile, computed rather than published
County seat
Corning
Seat of county government.
Established
1853
172 years ago
Largest city
Corning city
Population 1,511.

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 Adams 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 Adams County, Iowa 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 621 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 Adams County ranks

Position among the 99 counties of Iowa, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IowaNationally
Population3,61799th of 992,913th of 3,144
Land area423.4 sq mi92nd of 992,393rd of 3,144
Population density8.5 per sq mi99th of 992,621st of 3,144
Median household income$71,87543rd of 991,058th of 3,143

Full data for Adams County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population3,617Vintage 2025 Population Estimates
Population in 20203,710Vintage 2025 Population Estimates
2020 estimates base?3,708Vintage 2025 Population Estimates
Land area423.4 sq mi2025 Gazetteer Files
Water area2.1 sq mi2025 Gazetteer Files
Total area425.5 sq mi2025 Gazetteer Files
Population density?8.5 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$71,875American Community Survey 2020-2024 5-Year Estimates
Median home value$131,600American Community Survey 2020-2024 5-Year Estimates
Median age46.3American Community Survey 2020-2024 5-Year Estimates
Households1,540American Community Survey 2020-2024 5-Year Estimates
Housing units1,889American 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
-12
34 births, 46 deaths
Net migration
+29
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 Adams 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
Taylor CountyIowa24 mi5,835
Union CountyIowa18 mi11,829
Montgomery CountyIowa18 mi10,002
Adair CountyIowa12 mi7,403
Cass CountyIowa12 mi12,960
Page CountyIowaa single point14,856
Ringgold CountyIowaa single point4,642

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

All 99 counties of Iowa

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

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