Allamakee County area

Allamakee County, Iowa covers 658.8 square miles: 639.1 square miles of land and 19.7 square miles of water. Its county seat is Waukon. An estimated 14,238 people lived there in 2025.

Official Census measurements · GEOID 190052026 Gazetteer · retrieved September 27, 2026
Land area639.1 mi²
Water area19.7 mi²
Population (2025)14,238
People per mi²22

County outline

Generalized outline of Allamakee County, Iowa
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Allamakee County is located

Allamakee County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 97% of Allamakee County’s measured area and water for 3%. Its combined area converts to 1,706.3 square kilometers or approximately 421,631 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land639.0711,655.186409,005.4
Water19.72751.09312,625.3
Total658.7981,706.279421,630.7

How Allamakee County compares

By original Census land area, Allamakee County ranks #18 of 99 in Iowa and #1488 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.122 times the Iowa county-equivalent median of 569.6 square miles. It accounts for 1.1% of the combined county land area in the state.

See the complete Iowa ranking · What counts as a county equivalent?

Population and density of Allamakee County

The Census Bureau estimates that 14,238 people lived in Allamakee County on July 1, 2025. That ranks #2,211 of 3,222 county equivalents nationally and #55 of 99 in Iowa. Since the April 1, 2020 estimates base of 14,062, the population has grown by 176 (+1.3%), compared with +1.5% for Iowa as a whole.

With 639.1 square miles of land, that is 22 people per square mile (8.6 per km²), placing Allamakee County #2,235 nationally for density and #64 in Iowa. The median county equivalent has 47 people per square mile; the Iowa median is 26. Put another way, there are about 29 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate14,07213,97714,09514,16314,20614,238
Change—−95+118+68+43+32

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Allamakee County

6 incorporated places lie at least partly in Allamakee County. Together they are home to 7,758 people (54.5%); the other 6,480 (45.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Waukon city, with 3,849 residents in the county. Among places with at least 1,000 residents in 2020, Waukon city grew fastest since then (+0.7%).

Incorporated placePopulation 2025Since 2020Land mi²
Waukon cityCounty seat3,849+0.7%2.839
Postville cityAlso in 1 other county2,138−4.4%2.142
Lansing city957−0.3%1.08
New Albin city428−1.4%0.251
Harpers Ferry city274+5.4%0.64
Waterville city112+3.7%0.354

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Allamakee County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Allamakee County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.

ZIP codes

10 ZIP Code Tabulation Areas have land in Allamakee County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

52101521405214652151521565215952160521625217052172

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Allamakee County

Allamakee County shares a land border with 5 county equivalents, including 3 in Wisconsin and Minnesota. It has more land than 2 of them. The largest neighbor is Vernon County (791.6 mi²) and the smallest is Houston County (552.1 mi²). Together with its neighbors, Allamakee County forms a block of 4,021.9 mi² of land, of which it holds 15.9%.

Map of Allamakee County and the 5 county equivalents that border it Winneshiek County, Iowa: 689.8 mi² landCrawford County, Wisconsin: 570.8 mi² landClayton County, Iowa: 778.5 mi² landHouston County, Minnesota: 552.1 mi² landVernon County, Wisconsin: 791.6 mi² land
Allamakee County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. AllamakeeCompare
Vernon CountyWisconsin791.61.2× largerCompare
Clayton County778.51.2× largerCompare
Winneshiek County689.81.1× largerCompare
Crawford CountyWisconsin570.81.1× smallerCompare
Houston CountyMinnesota552.11.2× smallerCompare

How big is Allamakee County compared with U.S. states?

Allamakee County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.6 times as much. Iowa’s county land could hold about 87 areas the size of Allamakee County.

Land area: Allamakee County and the closest-sized states
Allamakee County639.1 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 25.3 miles (40.7 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Allamakee County?

Allamakee County has more land than 1,734 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Allamakee County639.1 mi²
Iowa median569.6 mi²
National median604.5 mi²

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Allamakee County at #1,541 nationally by total area, 53 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 3%, compared with a national county-equivalent median of 1.2% — 1.8 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Allamakee County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1487Clay County, Arkansas639.2Compare
#1488Allamakee County, Iowa639.1This county
#1489Chautauqua County, Kansas638.9Compare

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.

Representative coordinates

The Census internal point is 43.274964, -91.382751. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.

Source and precision

U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,655,186,559 m²; AWATER: 51,091,696 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Allamakee County?

Allamakee County, Iowa has 639.1 square miles (1,655.2 km²) of land and 19.7 square miles of water, for a total area of 658.8 square miles. It ranks #1488 of 3,222 U.S. county equivalents by land area.

Is Allamakee County the largest county in Iowa?

No. Allamakee County ranks #18 of 99 in Iowa by land area. The largest is Kossuth County, with 972.7 square miles of land.

What counties border Allamakee County?

Allamakee County shares a land border with Winneshiek County, Crawford County, Wisconsin, Clayton County, Houston County, Minnesota, and Vernon County, Wisconsin.

What is the population of Allamakee County?

The Census Bureau estimates Allamakee County had 14,238 residents on July 1, 2025, ranking #2,211 of 3,222 county equivalents. That is 22 people per square mile of land.

What is the county seat of Allamakee County?

The county seat of Allamakee County is Waukon.

What cities and towns are in Allamakee County?

Allamakee County has 6 incorporated places. The most populous five are Waukon city, Postville city, Lansing city, New Albin city, and Harpers Ferry city; 6,480 residents live outside any incorporated place.

Is Allamakee County part of a metropolitan area?

No. Allamakee County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Allamakee County?

10 ZIP Code Tabulation Areas have land in Allamakee County, and 8 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Allamakee County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.6 times as much land.

How many acres of land are in Allamakee County?

The land measurement converts to approximately 409,005 acres. Including water, total area is approximately 421,631 acres. One square mile equals 640 acres.

Why might another source show a different area?

Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.

Can this establish a property boundary?

No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.

Cite this county

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