County Maps US

Poweshiek County, Iowa

A county in Iowa, ranked 37 of 99 by population.

CountyFIPS 19157

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

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Population
18,368
-270 (-1.4%) since 2020
Land area
584.9
square miles. A further 0.2% of the total area is water
Population density
31.4
people per square mile, computed rather than published
County seat
Montezuma
Seat of county government.
Established
1843
182 years ago
Largest city
Grinnell city
Population 9,430.

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 Poweshiek 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 Poweshiek 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 793 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 Poweshiek 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
Population18,36837th of 991,914th of 3,144
Land area584.9 sq mi27th of 991,681st of 3,144
Population density31.4 per sq mi37th of 991,884th of 3,144
Median household income$67,39170th of 991,397th of 3,143

Full data for Poweshiek County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population18,368Vintage 2025 Population Estimates
Population in 202018,638Vintage 2025 Population Estimates
2020 estimates base?18,664Vintage 2025 Population Estimates
Land area584.9 sq mi2025 Gazetteer Files
Water area1.1 sq mi2025 Gazetteer Files
Total area586.1 sq mi2025 Gazetteer Files
Population density?31.4 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$67,391American Community Survey 2020-2024 5-Year Estimates
Median home value$209,300American Community Survey 2020-2024 5-Year Estimates
Median age41.0American Community Survey 2020-2024 5-Year Estimates
Households7,804American Community Survey 2020-2024 5-Year Estimates
Housing units8,975American 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
-55
167 births, 222 deaths
Net migration
+1
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 Poweshiek 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
Jasper CountyIowa25 mi38,153
Iowa CountyIowa24 mi16,504
Tama CountyIowa24 mi16,796
Mahaska CountyIowa18 mi21,880
Keokuk CountyIowa5.9 mi9,797
Benton CountyIowaa single point26,004
Marshall CountyIowaa single point39,890

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.