County outline
Where Lee County is located
Area breakdown
Land accounts for 96% of Lee County’s measured area and water for 4%. Its combined area converts to 1,395.7 square kilometers or approximately 344,889 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 517.55 | 1,340.448 | 331,232 |
| Water | 21.339 | 55.268 | 13,657 |
| Total | 538.889 | 1,395.716 | 344,889 |
How Lee County compares
By original Census land area, Lee County ranks #67 of 99 in Iowa and #2016 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.909 times the Iowa county-equivalent median of 569.6 square miles. It accounts for 0.9% of the combined county land area in the state.
See the complete Iowa ranking · What counts as a county equivalent?
Population and density of Lee County
The Census Bureau estimates that 32,306 people lived in Lee County on July 1, 2025. That ranks #1,426 of 3,222 county equivalents nationally and #22 of 99 in Iowa. Since the April 1, 2020 estimates base of 33,552, the population has declined by 1,246 (−3.7%), compared with +1.5% for Iowa as a whole.
With 517.6 square miles of land, that is 62 people per square mile (24 per km²), placing Lee County #1,359 nationally for density and #18 in Iowa. The median county equivalent has 47 people per square mile; the Iowa median is 26. Put another way, there are about 10 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 33,527 | 33,265 | 32,783 | 32,502 | 32,480 | 32,306 |
| Change | — | −262 | −482 | −281 | −22 | −174 |
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 Lee County
8 incorporated places lie at least partly in Lee County. Together they are home to 22,262 people (68.9%); the other 10,044 (31.1%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Fort Madison city, with 9,935 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Fort Madison cityCounty seat | 9,935 | −3.7% | 9.665 |
| Keokuk cityCounty seat | 9,510 | −4% | 9.099 |
| West Point city | 901 | −2.8% | 0.636 |
| Donnellson city | 808 | −9.2% | 1.273 |
| Montrose city | 745 | +0.4% | 1.209 |
| Franklin city | 133 | +1.5% | 0.156 |
| Houghton city | 126 | −3.1% | 0.3 |
| St. Paul city | 104 | −3.7% | 0.38 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Lee County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Lee County is a central county of the Fort Madison, IA Micropolitan Statistical Area. Lee County is the area’s only county equivalent, so the micro area has the same 517.6 square miles of land. By combined land it ranks #422 of 542 micropolitan areas, and #425 by population. It belongs to the Burlington-Fort Madison, IA-IL Combined Statistical Area.
ZIP codes
13 ZIP Code Tabulation Areas have land in Lee County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.
52619526245262552626526275263052631526325263952649526565265752658
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 Lee County
Lee County shares a land border with 6 county equivalents, including 3 in Illinois and Missouri. It has more land than 5 of them. The largest neighbor is Hancock County (793.7 mi²) and the smallest is Henderson County (378.8 mi²). Together with its neighbors, Lee County forms a block of 3,529.9 mi² of land, of which it holds 14.7%.
| Bordering county equivalent | Land mi² | Size vs. Lee | Compare |
|---|---|---|---|
| Hancock CountyIllinois | 793.7 | 1.5× larger | Compare |
| Clark CountyMissouri | 504.6 | about the same | Compare |
| Van Buren County | 484.8 | 1.1× smaller | Compare |
| Henry County | 434.3 | 1.2× smaller | Compare |
| Des Moines County | 416.1 | 1.2× smaller | Compare |
| Henderson CountyIllinois | 378.8 | 1.4× smaller | Compare |
How big is Lee County compared with U.S. states?
Lee County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2 times as much. Iowa’s county land could hold about 108 areas the size of Lee County.
Another way to picture it: the same land area would fill a square about 22.7 miles (36.6 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 Lee County?
Lee County has more land than 1,206 of the other 3,221 county equivalents in the dataset.
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 Lee County at #2,045 nationally by total area, 29 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 4%, compared with a national county-equivalent median of 1.2% — 2.8 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 Lee County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2015 | Midland County, Michigan | 518.4 | Compare |
| #2016 | Lee County, Iowa | 517.6 | This county |
| #2017 | Putnam County, Missouri | 517.3 | Compare |
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 40.647588, -91.477157. 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: 1,340,448,530 m²; AWATER: 55,266,760 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Lee County?
Lee County, Iowa has 517.6 square miles (1,340.4 km²) of land and 21.3 square miles of water, for a total area of 538.9 square miles. It ranks #2016 of 3,222 U.S. county equivalents by land area.
Is Lee County the largest county in Iowa?
No. Lee County ranks #67 of 99 in Iowa by land area. The largest is Kossuth County, with 972.7 square miles of land.
What counties border Lee County?
Lee County shares a land border with Hancock County, Illinois, Clark County, Missouri, Des Moines County, Henry County, Van Buren County, and Henderson County, Illinois.
What is the population of Lee County?
The Census Bureau estimates Lee County had 32,306 residents on July 1, 2025, ranking #1,426 of 3,222 county equivalents. That is 62 people per square mile of land.
What is the county seat of Lee County?
Lee County has two county seats: Fort Madison and Keokuk.
What cities and towns are in Lee County?
Lee County has 8 incorporated places. The most populous five are Fort Madison city, Keokuk city, West Point city, Donnellson city, and Montrose city; 10,044 residents live outside any incorporated place.
Is Lee County part of a metropolitan area?
Yes. It is a central county of the Fort Madison, IA Micropolitan Statistical Area.
How many ZIP codes are in Lee County?
13 ZIP Code Tabulation Areas have land in Lee County, and 11 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Lee County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2 times as much land.
How many acres of land are in Lee County?
The land measurement converts to approximately 331,232 acres. Including water, total area is approximately 344,889 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.