County outline
Where Blue Earth County is located
Area breakdown
Land accounts for 97.7% of Blue Earth County’s measured area and water for 2.3%. Its combined area converts to 1,982.8 square kilometers or approximately 489,972 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 747.837 | 1,936.889 | 478,615.7 |
| Water | 17.745 | 45.959 | 11,356.8 |
| Total | 765.582 | 1,982.848 | 489,972.5 |
How Blue Earth County compares
By original Census land area, Blue Earth County ranks #34 of 87 in Minnesota and #1180 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.109 times the Minnesota county-equivalent median of 674.6 square miles. It accounts for 0.9% of the combined county land area in the state.
See the complete Minnesota ranking · What counts as a county equivalent?
Population and density of Blue Earth County
The Census Bureau estimates that 70,634 people lived in Blue Earth County on July 1, 2025. That ranks #793 of 3,222 county equivalents nationally and #13 of 87 in Minnesota. Since the April 1, 2020 estimates base of 69,117, the population has grown by 1,517 (+2.2%), compared with +2.2% for Minnesota as a whole.
With 747.8 square miles of land, that is 94 people per square mile (36 per km²), placing Blue Earth County #1,037 nationally for density and #16 in Minnesota. The median county equivalent has 47 people per square mile; the Minnesota median is 27. Put another way, there are about 6.8 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 69,202 | 69,387 | 70,108 | 70,328 | 70,200 | 70,634 |
| Change | — | +185 | +721 | +220 | −128 | +434 |
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 Blue Earth County
Blue Earth County is divided into 35 municipalities and townships. In Minnesota, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Mankato city, with 46,524 residents (65.9% of the county). The largest by land is Judson township, at 36.5 mi², or 4.9% of the county’s land. Among those with at least 1,000 residents in 2020, Madison Lake city grew fastest since then (+5.2%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Mankato cityCounty seat | 46,524 | +4.4% | 19.9 | 2.7% |
| Eagle Lake city | 3,357 | +2.3% | 1.925 | 0.3% |
| Lake Crystal city | 2,470 | −2.6% | 2.082 | 0.3% |
| Mankato townshipCounty seat | 1,720 | −2.1% | 24.1 | 3.2% |
| Mapleton city | 1,622 | −4.9% | 1.443 | 0.2% |
| South Bend township | 1,550 | −2.2% | 16.4 | 2.2% |
| Madison Lake city | 1,315 | +5.2% | 1.372 | 0.2% |
| Decoria township | 1,100 | −2.1% | 35.9 | 4.8% |
| Rapidan township | 1,024 | −2.8% | 35.1 | 4.7% |
| Lime township | 930 | −1.7% | 15.4 | 2.1% |
| Garden City township | 823 | −2.1% | 32.2 | 4.3% |
| Le Ray township | 744 | −2.1% | 31.9 | 4.3% |
| St. Clair city | 707 | −4.6% | 0.649 | 0.1% |
| Jamestown township | 662 | −2.2% | 14.2 | 1.9% |
| Good Thunder city | 536 | −3.9% | 0.627 | 0.1% |
Show the other 20 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Judson township | 517 | −2.6% | 36.5 |
| Amboy city | 507 | −5.6% | 0.32 |
| McPherson township | 414 | −2.6% | 34.8 |
| Beauford township | 376 | −2.6% | 35.6 |
| Vernon Center city | 315 | −4.3% | 0.489 |
| Medo township | 312 | −2.8% | 35 |
| Lyra township | 288 | −3% | 35.1 |
| Butternut Valley township | 287 | −2.7% | 35.3 |
| Skyline city | 283 | −2.7% | 0.197 |
| Mapleton township | 272 | −2.5% | 34.2 |
| Cambria township | 248 | −2% | 19.3 |
| Shelby township | 239 | −2.8% | 35.2 |
| Vernon Center township | 239 | −1.6% | 35.1 |
| Sterling township | 235 | −2.9% | 34.4 |
| Pemberton city | 219 | −5.2% | 0.188 |
| Danville township | 217 | −2.7% | 35.8 |
| Lincoln township | 205 | −2.4% | 35.9 |
| Pleasant Mound township | 193 | −3.5% | 35.9 |
| Ceresco township | 178 | −3.3% | 35.7 |
| Minnesota Lake city | 6 | 0% | 0.065 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Blue Earth County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Blue Earth County is a central county of the Mankato, MN Metropolitan Statistical Area. Its 2 county equivalents have 104,907 residents on 1,196.2 square miles of land; Blue Earth County accounts for 62.5% of the land and 67.3% of the residents. By combined land it ranks #259 of 393 metropolitan areas, and #359 by population. It belongs to the Mankato-New Ulm, MN Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Blue Earth County | 70,634 | 747.8 |
| Nicollet County | 34,273 | 448.3 |
ZIP codes
20 ZIP Code Tabulation Areas have land in Blue Earth County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.
5600156003560105602456034560375604156048560505605556060560625606356065560685607356078560805608856090
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 Blue Earth County
Blue Earth County shares a land border with 7 county equivalents. It has more land than every one of them. The largest neighbor is Faribault County (712.5 mi²) and the smallest is Waseca County (423.4 mi²). Together with its neighbors, Blue Earth County forms a block of 4,539.3 mi² of land, of which it holds 16.5%.
| Bordering county equivalent | Land mi² | Size vs. Blue Earth | Compare |
|---|---|---|---|
| Faribault County | 712.5 | about the same | Compare |
| Martin County | 712.3 | about the same | Compare |
| Brown County | 611.3 | 1.2× smaller | Compare |
| Le Sueur County | 448.8 | 1.7× smaller | Compare |
| Nicollet County | 448.3 | 1.7× smaller | Compare |
| Watonwan County | 435 | 1.7× smaller | Compare |
| Waseca County | 423.4 | 1.8× smaller | Compare |
How big is Blue Earth County compared with U.S. states?
Blue Earth County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.4 times as much. Minnesota’s county land could hold about 106 areas the size of Blue Earth County.
Another way to picture it: the same land area would fill a square about 27.3 miles (44 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 Blue Earth County?
Blue Earth County has more land than 2,042 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 Blue Earth County at #1,253 nationally by total area, 73 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 2.3%, compared with a national county-equivalent median of 1.2% — 1.1 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 Blue Earth County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1179 | Mills County, Texas | 748.2 | Compare |
| #1180 | Blue Earth County, Minnesota | 747.8 | This county |
| #1181 | Karnes County, Texas | 747.8 | 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 44.028593, -94.064280. 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: 1,936,887,877 m²; AWATER: 45,959,537 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 Blue Earth County?
Blue Earth County, Minnesota has 747.8 square miles (1,936.9 km²) of land and 17.7 square miles of water, for a total area of 765.6 square miles. It ranks #1180 of 3,222 U.S. county equivalents by land area.
Is Blue Earth County the largest county in Minnesota?
No. Blue Earth County ranks #34 of 87 in Minnesota by land area. The largest is St. Louis County, with 6,248.1 square miles of land.
What counties border Blue Earth County?
Blue Earth County shares a land border with Waseca County, Nicollet County, Faribault County, Watonwan County, Le Sueur County, Brown County, and Martin County.
What is the population of Blue Earth County?
The Census Bureau estimates Blue Earth County had 70,634 residents on July 1, 2025, ranking #793 of 3,222 county equivalents. That is 94 people per square mile of land.
What is the county seat of Blue Earth County?
The county seat of Blue Earth County is Mankato.
What cities and towns are in Blue Earth County?
Blue Earth County has 35 county subdivisions (cities, towns and townships). The most populous five are Mankato city, Eagle Lake city, Lake Crystal city, Mankato township, and Mapleton city.
Is Blue Earth County part of a metropolitan area?
Yes. It is a central county of the Mankato, MN Metropolitan Statistical Area, which has 2 county equivalents and 104,907 residents.
How many ZIP codes are in Blue Earth County?
20 ZIP Code Tabulation Areas have land in Blue Earth 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 Blue Earth County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.4 times as much land.
How many acres of land are in Blue Earth County?
The land measurement converts to approximately 478,616 acres. Including water, total area is approximately 489,972 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.