Blue Earth County is a county in Minnesota, United States, centred on the confluence of the Blue Earth and Minnesota rivers in the south-central part of the state. It had a population of 69,112 at the 2020 census and covers 748 square miles (1,940 km2) of land plus 18 square miles (47 km2) of water, centred near 44°02′N 94°04′W.
Mankato is the county seat; its postal code is 56001. The county holds 12 incorporated cities, 23 civil townships and a handful of unincorporated communities and manufactured-home communities. It sits in the Central time zone and forms the core of the Mankato–North Mankato metropolitan area.
Towns & Villages in Blue Earth County
Blue Earth County has 12 incorporated cities, led by Mankato, plus several small unincorporated communities and manufactured-home communities scattered through the surrounding townships. In the table below, “City · seat” marks the county seat, “City” marks other incorporated cities, and “Unincorp.” marks a named community, hamlet, or manufactured-home community with no municipal government of its own.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Mankato | City · seat | Mankato Twp. | 44,488 | 56001 |
| Eagle Lake | City | Le Ray Twp. | 2,951 | 56024 |
| Lake Crystal | City | Lyra Twp. | 2,529 | 56055 |
| Mapleton | City | Mapleton Twp. | 1,770 | 56065 |
| Madison Lake | City | — | 1,188 | 56063 |
| Saint Clair | City | — | 810 | 56080 |
| Good Thunder | City | McPherson Twp. | 615 | 56037 |
| Amboy | City | Shelby Twp. | 547 | 56010 |
| Skyline | City | — | — | — |
| Vernon Center | City | Vernon Center Twp. | 289 | 56090 |
| Garden City | City | Garden City Twp. | 197 | 56034 |
| Pemberton | City | Decoria Twp. | 231 | 56078 |
| Cambria | Unincorp. | Cambria Twp. | — | — |
| Perth | Unincorp. | McPherson Twp. | — | — |
| Butternut | Unincorp. | Butternut Valley Twp. | — | — |
| Judson | Unincorp. | Judson Twp. | — | — |
| Rapidan | Unincorp. | Rapidan Twp. | — | — |
| LeHillier | Unincorp. | — | — | — |
| Sterling Center | Unincorp. | Sterling Twp. | — | — |
| Willow Creek | Unincorp. | — | — | — |
| Belle Haven | Unincorp. | — | — | — |
| Benning | Unincorp. | — | — | — |
| Boening MH Park | Unincorp. | — | — | — |
| Eagle Lake Regency | Unincorp. | Le Ray Twp. | — | — |
| Eastwood Manor MH Park | Unincorp. | — | — | — |
| High Ciara MH Park | Unincorp. | — | — | — |
| Hoppe MH Park | Unincorp. | — | — | — |
| Knollwood Park | Unincorp. | — | — | — |
| Lime Valley MH Park | Unincorp. | Lime Twp. | — | — |
| Pleasant Hill Manor | Unincorp. | — | — | — |
| Rambush Estates II | Unincorp. | — | — | — |
| Southhaven MH Park | Unincorp. | — | — | — |
| University Park of Mankato | Unincorp. | Mankato Twp. | — | — |
Two names in this list are easily confused: Vernon Center the city and Vernon Center Township share a name but are separate governments, and Eagle Lake city sits inside Le Ray Township while nearby Eagle Lake Regency is a distinct manufactured-home community, not a neighborhood of the city itself.
Townships
Blue Earth County has 23 organized civil townships. Detailed 2020 township-level population figures were not available from the sources consulted for this update, so the table below lists each township with its best-known main settlement; unnamed cells mean the township is mostly open countryside with no platted community.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Mankato Township | — | Surrounds the city of Mankato; University Park of Mankato |
| Le Ray Township | — | Eagle Lake, Eagle Lake Regency |
| Lyra Township | — | Lake Crystal |
| Mapleton Township | — | Mapleton |
| Garden City Township | — | Garden City |
| Decoria Township | — | Pemberton |
| McPherson Township | — | Good Thunder, Perth |
| Shelby Township | — | Amboy |
| Vernon Center Township | — | Vernon Center |
| Judson Township | — | Judson |
| Rapidan Township | — | Rapidan |
| Cambria Township | — | Cambria |
| Butternut Valley Township | — | Butternut |
| Sterling Township | — | Sterling Center |
| Lime Township | — | Lime Valley MH Park |
| Beauford Township | — | — |
| Ceresco Township | — | — |
| Danville Township | — | — |
| Jamestown Township | — | — |
| Lincoln Township | — | — |
| Medo Township | — | — |
| Pleasant Mound Township | — | — |
| South Bend Township | — | — |
ZIP Codes
- 56001 — Mankato (also serves the city’s south side)
- 56002 — Mankato (PO Box only)
- 56010 — Amboy
- 56024 — Eagle Lake
- 56034 — Garden City
- 56037 — Good Thunder
- 56055 — Lake Crystal
- 56063 — Madison Lake
- 56065 — Mapleton
- 56078 — Pemberton
- 56080 — Saint Clair (PO Box only)
- 56090 — Vernon Center
Skyline and the county’s smaller unincorporated and manufactured-home communities use the ZIP code of their nearest post office town rather than a code of their own.
Geography
Blue Earth County lies in the Minnesota River valley where the Blue Earth River joins the Minnesota River at Mankato. The terrain is a mix of river bluffs along the Minnesota and Blue Earth valleys and gently rolling farmland on the upland prairie between them; row-crop agriculture covers most of the county outside the Mankato–North Mankato urban core.
The county borders Nicollet County to the north, Le Sueur County to the northeast, Waseca County to the east, Faribault County to the south, Martin County to the southwest, Watonwan County to the west, and Brown County to the northwest.
Demographics
Blue Earth County had 69,112 residents at the 2020 census. Mankato, the county seat, is by far the largest place with 44,488 people, followed by North Mankato (across the county line in Nicollet County) and Eagle Lake at 2,951. Median household income countywide runs above the Minnesota median of $85,086, reflecting Mankato’s role as a regional employment and healthcare hub. With 748 square miles of land, the county’s overall density works out to roughly 92 people per square mile, concentrated heavily in and around Mankato.
Economy & Local Life
Mankato anchors the county’s economy as the retail, healthcare, and higher-education center for a wide swath of south-central Minnesota. Minnesota State University, Mankato and Mayo Clinic Health System—Mankato are among the area’s largest employers, alongside food processors and manufacturers serving the surrounding farm economy. Outside the city, agriculture (corn and soybeans) dominates land use across the townships. Mankato hosts the annual Mahkato Wacipi (Pow Wow) each September, one of the largest Dakota gatherings in the region.
History
Blue Earth County was organized on March 5, 1853, carved from a larger unorganized territory in the young Minnesota Territory. Its name comes from the Blue Earth River, itself named for deposits of blue-green clay once visible along its banks. Mankato, platted the same year, grew quickly as a river landing and became the county seat; the county and city both figure in the history of the 1862 U.S.–Dakota War, including the 1862 mass execution at Mankato that remains the largest single-day execution in U.S. history.
Getting There
U.S. Highways 14 and 169 and Minnesota State Highways 22, 30, 60, and 68 cross the county, meeting at Mankato.
- Mankato — county seat, at the junction of US 14 and US 169
- Lake Crystal — about 10 miles west of Mankato via US 14
- Eagle Lake — about 6 miles east of Mankato via US 14
- Mapleton — about 15 miles south of Mankato via US 169
Mankato Regional Airport, just south of the city, offers commercial commuter service; Minneapolis–Saint Paul International Airport is about 80 miles to the northeast.
Frequently Asked Questions
Where is Blue Earth County located?
It is in south-central Minnesota, at the confluence of the Blue Earth and Minnesota rivers, about 80 miles southwest of the Twin Cities.
What is the population of Blue Earth County?
69,112 people at the 2020 census.
How big is Blue Earth County?
748 square miles of land and 18 square miles of water, 766 square miles in total.
What is the county seat of Blue Earth County?
Mankato is the county seat.
How many towns are in Blue Earth County?
The county has 12 incorporated cities plus a number of unincorporated communities spread across its 23 townships.
What ZIP codes are in Blue Earth County?
Codes include 56001/56002 (Mankato), 56010 (Amboy), 56024 (Eagle Lake), 56034 (Garden City), 56037 (Good Thunder), 56055 (Lake Crystal), 56063 (Madison Lake), 56065 (Mapleton), 56078 (Pemberton), 56080 (Saint Clair), and 56090 (Vernon Center).
Why is it called Blue Earth County?
It is named for the Blue Earth River, which itself takes its name from deposits of blue-green clay once visible along the riverbank.
More counties in this state: Towns and villages in Minnesota.