County Maps US

Columbia County, Wisconsin

A county in Wisconsin, ranked 26 of 72 by population.

CountyFIPS 55021

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

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Population
58,132
-402 (-0.7%) since 2020
Land area
765.6
square miles. A further 3.8% of the total area is water
Population density
75.9
people per square mile, computed rather than published
County seat
Portage
Seat of county government.
Established
1846
179 years ago
Largest city
Portage city
Population 9,956.

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 Columbia 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 Columbia County, Wisconsin 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 542 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 Columbia County ranks

Position among the 72 counties of Wisconsin, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn WisconsinNationally
Population58,13226th of 72916th of 3,144
Land area765.6 sq mi34th of 721,136th of 3,144
Population density75.9 per sq mi26th of 721,123rd of 3,144
Median household income$85,3518th of 72413th of 3,143

Full data for Columbia County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population58,132Vintage 2025 Population Estimates
Population in 202058,534Vintage 2025 Population Estimates
2020 estimates base?58,494Vintage 2025 Population Estimates
Land area765.6 sq mi2025 Gazetteer Files
Water area30.4 sq mi2025 Gazetteer Files
Total area796 sq mi2025 Gazetteer Files
Population density?75.9 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$85,351American Community Survey 2020-2024 5-Year Estimates
Median home value$283,200American Community Survey 2020-2024 5-Year Estimates
Median age43.7American Community Survey 2020-2024 5-Year Estimates
Households24,158American Community Survey 2020-2024 5-Year Estimates
Housing units26,880American 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
-88
561 births, 649 deaths
Net migration
+214
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 Columbia 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
Sauk CountyWisconsin37 mi66,652
Dane CountyWisconsin37 mi590,375
Dodge CountyWisconsin24 mi89,097
Marquette CountyWisconsin18 mi15,927
Green Lake CountyWisconsin13 mi19,305
Adams CountyWisconsin9.3 mi21,752
Juneau CountyWisconsin240 ft26,649

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

All 72 counties of Wisconsin

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

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