County Maps US

Iowa County Map

Iowa has 99 counties. Together they cover 55,854 sq mi of land and 3,238,387 people.

Neighbouring areas are given different colours so their shared borders read clearly. These colours carry no data.

Boundaries from the 2025 Census cartographic boundary file, generalised so that no point moves by more than half a pixel at this width. Select any area to open its page.
Counties
99
9th most of the 51 states and DC
Population
3,238,387
32nd largest
Land area
55,854
square miles
Density
58.0
people per square mile, computed

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. Retrieved 30 August 2026.

Download this map

Free to use and redistribute. The boundaries are public-domain Census Bureau data; attribution to County Maps US is appreciated but not required.

Satellite view

Aerial imagery of Iowa with the state boundary drawn on top. County lines are not drawn here: at this scale they would bury the picture, and the map above already carries them.

Aerial view of 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 548 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.

The extremes of Iowa

Most populous

Polk County

516,546

Least populous

Adams County

3,617

Largest by land area

Kossuth County

972.7 sq mi

Smallest by land area

Dickinson County

380.5 sq mi

Most densely populated

Polk County

902 per sq mi

Highest median household income

Dallas County

$102,379

Which is the largest county in Iowa? The answer depends on whether you mean area or population.

The counties, by shape

Every one, drawn to its own scale so the small ones stay recognisable. Shape alone is not a size comparison; the table below carries the areas.

What the map does not say

The counties of Iowa are nowhere near the same size. Kossuth County covers 972.7 sq mi of land, 2.6 times the 380.5 sq mi of Dickinson County. People are spread even less evenly: Polk County packs 902 per sq mi while Adams County holds 8.5 per sq mi.

They were not drawn in one sitting either. Dubuque County dates to 1834, and the boundaries were still being redrawn when Osceola County was organised in 1871, 37 years later. Founding years come from Wikidata and are worth checking against the county's own history before citing.

Water is part of the picture too: 5.8% of Dickinson County is water, the most in the state, which is why its land area and total area disagree. And 73 of the 99 counties here share their names with counties in other states, so searching by name alone can land in the wrong place; the A to Z index lists every duplicate.

All 99 counties of Iowa

Sortable on any column. This table doubles as the text alternative to the map above: every area is a link, in alphabetical order, whether or not the map renders.

The 99 counties of Iowa, with population, land area, density, median household income, county seat and FIPS code.
NamePopulationLand areaDensityMedian incomeSeatFIPS
Adair County7,403569.3 sq mi13.0 per sq mi$68,092Greenfield19001
Adams County3,617423.4 sq mi8.5 per sq mi$71,875Corning19003
Allamakee County14,238639.1 sq mi22.3 per sq mi$70,694Waukon19005
Appanoose County12,077497.3 sq mi24.3 per sq mi$54,934Centerville19007
Audubon County5,509443 sq mi12.4 per sq mi$58,229Audubon19009
Benton County26,004716.1 sq mi36.3 per sq mi$86,962Vinton19011
Black Hawk County131,532565.8 sq mi232 per sq mi$66,417Waterloo19013
Boone County26,799570.5 sq mi47.0 per sq mi$83,531Boone19015
Bremer County25,296435.5 sq mi58.1 per sq mi$86,784Waverly19017
Buchanan County20,883571.1 sq mi36.6 per sq mi$78,236Independence19019
Buena Vista County20,449574.9 sq mi35.6 per sq mi$71,719Storm Lake19021
Butler County14,049580.1 sq mi24.2 per sq mi$73,715Allison19023
Calhoun County9,562569.8 sq mi16.8 per sq mi$64,964Rockwell City19025
Carroll County20,303569.5 sq mi35.7 per sq mi$72,930Carroll19027
Cass County12,960564.3 sq mi23.0 per sq mi$63,013Atlantic19029
Cedar County18,359579.5 sq mi31.7 per sq mi$80,602Tipton19031
Cerro Gordo County42,372568.3 sq mi74.6 per sq mi$68,189Mason City19033
Cherokee County11,369576.9 sq mi19.7 per sq mi$71,269Cherokee19035
Chickasaw County11,663504.3 sq mi23.1 per sq mi$75,675New Hampton19037
Clarke County9,574431.1 sq mi22.2 per sq mi$71,641Osceola19039
Clay County16,202567.2 sq mi28.6 per sq mi$65,428Spencer19041
Clayton County16,845778.5 sq mi21.6 per sq mi$67,242Elkader19043
Clinton County46,002695 sq mi66.2 per sq mi$66,981Clinton19045
Crawford County16,237714.2 sq mi22.7 per sq mi$67,027Denison19047
Dallas County118,457588.2 sq mi201 per sq mi$102,379Adel19049
Davis County9,230502.2 sq mi18.4 per sq mi$77,194Bloomfield19051
Decatur County7,655531.9 sq mi14.4 per sq mi$59,044Leon19053
Delaware County17,674577.7 sq mi30.6 per sq mi$74,989Manchester19055
Des Moines County38,077416.1 sq mi91.5 per sq mi$62,928Burlington19057
Dickinson County18,077380.5 sq mi47.5 per sq mi$75,432Spirit Lake19059
Dubuque County99,381608.3 sq mi163 per sq mi$77,630Dubuque19061
Emmet County9,107395.9 sq mi23.0 per sq mi$63,730Estherville19063
Fayette County19,047730.8 sq mi26.1 per sq mi$60,165West Union19065
Floyd County14,901500.6 sq mi29.8 per sq mi$68,557Charles City19067
Franklin County9,868582 sq mi17.0 per sq mi$59,894Hampton19069
Fremont County6,522511.2 sq mi12.8 per sq mi$71,621Sidney19071
Greene County8,658569.6 sq mi15.2 per sq mi$63,409Jefferson19073
Grundy County12,361501.9 sq mi24.6 per sq mi$87,205Grundy Center19075
Guthrie County10,782590.6 sq mi18.3 per sq mi$77,711Guthrie Center19077
Hamilton County14,944576.7 sq mi25.9 per sq mi$72,432Webster City19079
Hancock County10,528571 sq mi18.4 per sq mi$70,601Garner19081
Hardin County16,455569.3 sq mi28.9 per sq mi$65,069Eldora19083
Harrison County14,623696.9 sq mi21.0 per sq mi$79,535Logan19085
Henry County19,349434.3 sq mi44.6 per sq mi$67,436Mount Pleasant19087
Howard County9,415473.2 sq mi19.9 per sq mi$67,446Cresco19089
Humboldt County9,409434.4 sq mi21.7 per sq mi$71,946Dakota City19091
Ida County6,777431.5 sq mi15.7 per sq mi$63,073Ida Grove19093
Iowa County16,504586.5 sq mi28.1 per sq mi$71,223Marengo19095
Jackson County19,288636 sq mi30.3 per sq mi$74,186Maquoketa19097
Jasper County38,153730.4 sq mi52.2 per sq mi$71,311Newton19099
Jefferson County15,291435.5 sq mi35.1 per sq mi$61,620Fairfield19101
Johnson County160,044613 sq mi261 per sq mi$74,935Iowa City19103
Jones County21,253575.6 sq mi36.9 per sq mi$73,531Anamosa19105
Keokuk County9,797579.2 sq mi16.9 per sq mi$62,329Sigourney19107
Kossuth County14,322972.7 sq mi14.7 per sq mi$67,697Algona19109
Lee County32,306517.6 sq mi62.4 per sq mi$62,382Keokuk19111
Linn County232,028717 sq mi324 per sq mi$77,649Cedar Rapids19113
Louisa County10,416401.8 sq mi25.9 per sq mi$77,354Wapello19115
Lucas County8,847430.7 sq mi20.5 per sq mi$61,793Chariton19117
Lyon County12,354587.6 sq mi21.0 per sq mi$76,746Rock Rapids19119
Madison County17,270561 sq mi30.8 per sq mi$90,855Winterset19121
Mahaska County21,880570.9 sq mi38.3 per sq mi$70,940Oskaloosa19123
Marion County34,192554.5 sq mi61.7 per sq mi$78,680Knoxville19125
Marshall County39,890572.5 sq mi69.7 per sq mi$73,315Marshalltown19127
Mills County14,793437.4 sq mi33.8 per sq mi$90,753Glenwood19129
Mitchell County10,650469.3 sq mi22.7 per sq mi$71,365Osage19131
Monona County8,539694.1 sq mi12.3 per sq mi$68,377Onawa19133
Monroe County7,406433.7 sq mi17.1 per sq mi$70,996Albia19135
Montgomery County10,002424.1 sq mi23.6 per sq mi$63,666Red Oak19137
Muscatine County41,853437.4 sq mi95.7 per sq mi$69,396Muscatine19139
O'Brien County14,220573 sq mi24.8 per sq mi$68,356Primghar19141
Osceola County5,980398.7 sq mi15.0 per sq mi$69,239Sibley19143
Page County14,856534.9 sq mi27.8 per sq mi$57,953Clarinda19145
Palo Alto County8,899563.9 sq mi15.8 per sq mi$72,781Emmetsburg19147
Plymouth County25,697862.8 sq mi29.8 per sq mi$83,251Le Mars19149
Pocahontas County6,819577.2 sq mi11.8 per sq mi$61,875Pocahontas19151
Polk County516,546572.7 sq mi902 per sq mi$83,576Des Moines19153
Pottawattamie County92,996951.3 sq mi97.8 per sq mi$73,602Council Bluffs19155
Poweshiek County18,368584.9 sq mi31.4 per sq mi$67,391Montezuma19157
Ringgold County4,642535.5 sq mi8.7 per sq mi$73,346Mount Ayr19159
Sac County9,525575 sq mi16.6 per sq mi$73,838Sac City19161
Scott County175,259458.1 sq mi383 per sq mi$78,277Davenport19163
Shelby County11,689590.8 sq mi19.8 per sq mi$72,738Harlan19165
Sioux County36,774767.9 sq mi47.9 per sq mi$86,098Orange City19167
Story County101,291572.5 sq mi177 per sq mi$69,685Nevada19169
Tama County16,796721 sq mi23.3 per sq mi$70,781Toledo19171
Taylor County5,835531.9 sq mi11.0 per sq mi$67,740Bedford19173
Union County11,829423.6 sq mi27.9 per sq mi$57,772Creston19175
Van Buren County7,131484.8 sq mi14.7 per sq mi$61,161Keosauqua19177
Wapello County35,210431.8 sq mi81.5 per sq mi$64,766Ottumwa19179
Warren County57,331569.7 sq mi101 per sq mi$94,588Indianola19181
Washington County22,667568.8 sq mi39.8 per sq mi$75,647Washington19183
Wayne County6,738525.5 sq mi12.8 per sq mi$61,964Corydon19185
Webster County36,838715.7 sq mi51.5 per sq mi$68,975Fort Dodge19187
Winnebago County10,251400.5 sq mi25.6 per sq mi$67,642Forest City19189
Winneshiek County19,733689.8 sq mi28.6 per sq mi$79,066Decorah19191
Woodbury County106,649872.9 sq mi122 per sq mi$73,658Sioux City19193
Worth County7,338400.1 sq mi18.3 per sq mi$78,008Northwood19195
Wright County12,801580.4 sq mi22.1 per sq mi$67,190Clarion19197

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; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Looking for Iowa County?

Iowa is also the name of 1 county in other states. If you meant one of those rather than the state of Iowa, they are listed here.

The ten most populous

  1. Polk County516,546
  2. Linn County232,028
  3. Scott County175,259
  4. Johnson County160,044
  5. Black Hawk County131,532
  6. Dallas County118,457
  7. Woodbury County106,649
  8. Story County101,291
  9. Dubuque County99,381
  10. Pottawattamie County92,996

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