Watonwan County is a county in Minnesota, United States, on the low, rolling farmland of the Minnesota River basin about 100 miles southwest of Minneapolis. It had a population of 11,253 at the 2020 census, up slightly from the prior decade after a long mid-century decline, and covers 440 square miles (1,139 km2) of land and water centred near 43°59′N 94°37′W.
St. James is the county seat, and its postal code is 56081. The county has eight incorporated cities — Butterfield, Darfur, La Salle, Lewisville, Madelia, Odin, Ormsby and St. James — plus several unincorporated communities, all organized across 12 civil townships. Watonwan County sits in the Central time zone and carries FIPS code 27165.
Towns & Villages in Watonwan County
St. James is the largest city and the seat of government; Madelia, the county’s original seat before an 1875 relocation, is the second largest. The rest are small farm towns and rail-line villages scattered across the townships below.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| St. James | City · seat | St. James Township | 4,793 | 56081 |
| Madelia | City | Madelia Township | 2,396 | 56062 |
| Butterfield | City | Butterfield Township | — | — |
| Lewisville | City | — | — | — |
| Odin | City | Odin Township | — | — |
| Ormsby | City | — | — | — |
| La Salle | City | — | — | — |
| Darfur | City | — | — | — |
| South Branch | Unincorp. | South Branch Township | — | — |
| Sveadahl | Unincorp. | — | — | — |
| Echols | Unincorp. | — | — | — |
| Grogan | Unincorp. | — | — | — |
| Tenmile Corner | Unincorp. | — | — | — |
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| St. James Township | — | St. James |
| Madelia Township | — | Madelia |
| Butterfield Township | — | Butterfield |
| Odin Township | — | Odin |
| South Branch Township | — | South Branch |
| Adrian Township | — | — |
| Antrim Township | — | — |
| Fieldon Township | — | — |
| Long Lake Township | — | — |
| Nelson Township | — | — |
| Riverdale Township | — | — |
| Rosendale Township | — | — |
ZIP Codes
- 56081 — St. James (also serves the surrounding township)
- 56062 — Madelia (also serves the surrounding township)
The smaller cities and unincorporated places largely share a St. James or Madelia postal route rather than carrying a ZIP code of their own.
Geography
Watonwan County lies on gently rolling till plain, carved by the Watonwan River and its tributaries, which drain the county and flow eastward through its northern townships toward the Blue Earth River. Small lakes, wetlands and drainage ditches dot the farmland, and the countryside slopes gradually northeastward. Nearly the whole county is in row-crop agriculture. Watonwan County borders Brown County to the north, Blue Earth County to the east, Martin County to the south, Jackson County to the southwest and Cottonwood County to the west.
Demographics
Watonwan County had 11,253 residents at the 2020 census, edging up to an estimated 11,459 in 2025 after decades of decline from a mid-1900s peak near 14,500. St. James and Madelia together hold more than half the county’s population, with the rest spread across small towns and farmsteads. Median household income runs below Minnesota’s 2023 ACS state figure of $85,086, reflecting the county’s agricultural economic base. Population density is light, at roughly 26 people per square mile of land.
Economy & Local Life
Farming drives the county — corn, soybeans and hog and dairy operations dominate wherever the land allows it, and grain elevators mark most of the small towns. St. James anchors the county’s retail, healthcare and light-manufacturing base and hosts St. James Municipal Airport, the county’s general-aviation field. Watonwan County’s biggest annual gathering is the Watonwan County Fair in St. James each August, drawing 4-H exhibits and livestock shows from across the county.
History
Minnesota’s territorial legislature created Watonwan County on February 25, 1860, carving it out of Brown County. The name comes from the Dakota word for the Watonwan River, commonly translated as “fish bait” or “plenty of fish.” Madelia served as the first county seat before St. James, better positioned on the rail line, took over the role in 1875. The county’s small towns grew up as depot stops along the railroads that crossed the farmland in the late 1800s.
Getting There
Minnesota Highways 4, 15, 30 and 60 cross the county and link its towns to the regional highway grid.
- Mankato — 30 miles northeast
- New Ulm — 25 miles north
- Fairmont — 25 miles south
- Windom — 25 miles west
The nearest commercial airport is Mankato Regional Airport; the nearest Amtrak service is the Empire Builder station in St. Paul, about 110 miles northeast.
Frequently Asked Questions
Where is Watonwan County, Minnesota?
It sits in south-central Minnesota, about 100 miles southwest of the Twin Cities, drained by the Watonwan River.
What is the St. James postcode?
56081.
What is the population of Watonwan County?
11,253 at the 2020 census, an estimated 11,459 as of 2025.
What is the county seat of Watonwan County?
St. James is the county seat; Madelia was the original seat until 1875.
How many cities are in Watonwan County?
Eight incorporated cities — Butterfield, Darfur, La Salle, Lewisville, Madelia, Odin, Ormsby and St. James — plus small unincorporated communities like Sveadahl and South Branch.
What does the name Watonwan mean?
It comes from a Dakota word for the river, usually translated as “fish bait” or “plenty of fish.”
What counties border Watonwan County?
Brown to the north, Blue Earth to the east, Martin to the south, Jackson to the southwest and Cottonwood to the west.
More counties in this state: Towns and villages in Minnesota.