County Maps US

Cass County, Iowa

A county in Iowa, ranked 58 of 99 by population.

CountyFIPS 19029

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

Download SVGFull Iowa map downloads

Population
12,960
-158 (-1.2%) since 2020
Land area
564.3
square miles. A further 0.1% of the total area is water
Population density
23.0
people per square mile, computed rather than published
County seat
Atlantic
Seat of county government.
Established
1851
174 years ago
Largest city
Atlantic city
Population 6,676.

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 Cass 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 Cass 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 790 by 800 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 Cass 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
Population12,96058th of 992,223rd of 3,144
Land area564.3 sq mi58th of 991,820th of 3,144
Population density23.0 per sq mi60th of 992,128th of 3,144
Median household income$63,01384th of 991,796th of 3,143

Full data for Cass County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population12,960Vintage 2025 Population Estimates
Population in 202013,118Vintage 2025 Population Estimates
2020 estimates base?13,129Vintage 2025 Population Estimates
Land area564.3 sq mi2025 Gazetteer Files
Water area0.69 sq mi2025 Gazetteer Files
Total area565 sq mi2025 Gazetteer Files
Population density?23.0 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$63,013American Community Survey 2020-2024 5-Year Estimates
Median home value$150,300American Community Survey 2020-2024 5-Year Estimates
Median age43.5American Community Survey 2020-2024 5-Year Estimates
Households5,844American Community Survey 2020-2024 5-Year Estimates
Housing units6,393American 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
-91
129 births, 220 deaths
Net migration
+47
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 Cass 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
Pottawattamie CountyIowa24 mi92,996
Adair CountyIowa24 mi7,403
Audubon CountyIowa18 mi5,509
Montgomery CountyIowa12 mi10,002
Adams CountyIowa12 mi3,617
Shelby CountyIowa5.9 mi11,689
Guthrie CountyIowaa single point10,782

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.