County Maps US

Boone County, Iowa

A county in Iowa, ranked 23 of 99 by population.

CountyFIPS 19015

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

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Population
26,799
+94 (+0.4%) since 2020
Land area
570.5
square miles. A further 0.6% of the total area is water
Population density
47.0
people per square mile, computed rather than published
County seat
Boone
Seat of county government.
Established
1846
179 years ago
Largest city
Boone city
Population 12,471.

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 Boone 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 Boone 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 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 Boone 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
Population26,79923rd of 991,546th of 3,144
Land area570.5 sq mi47th of 991,771st of 3,144
Population density47.0 per sq mi25th of 991,534th of 3,144
Median household income$83,53110th of 99466th of 3,143

Full data for Boone County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population26,799Vintage 2025 Population Estimates
Population in 202026,705Vintage 2025 Population Estimates
2020 estimates base?26,715Vintage 2025 Population Estimates
Land area570.5 sq mi2025 Gazetteer Files
Water area3.2 sq mi2025 Gazetteer Files
Total area573.6 sq mi2025 Gazetteer Files
Population density?47.0 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$83,531American Community Survey 2020-2024 5-Year Estimates
Median home value$212,400American Community Survey 2020-2024 5-Year Estimates
Median age42.4American Community Survey 2020-2024 5-Year Estimates
Households10,936American Community Survey 2020-2024 5-Year Estimates
Housing units12,041American 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
-74
253 births, 327 deaths
Net migration
+146
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 6 areas bordering Boone 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
Greene CountyIowa24 mi8,658
Story CountyIowa24 mi101,291
Dallas CountyIowa18 mi118,457
Hamilton CountyIowa12 mi14,944
Webster CountyIowa12 mi36,838
Polk CountyIowa6.1 mi516,546

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.