Mahaska County is a county in Iowa, United States, on the rolling farmland of the state’s south-central region. It had a population of 22,190 at the 2020 census and covers 573 square miles (1,480 km2), of which 571 square miles is land and 2.5 square miles is water, centred near 41°20′N 92°39′W.
Oskaloosa is the county seat, and its postal code is 52577. The county has 5 incorporated cities and roughly two dozen unincorporated communities, spread across 18 civil townships. Mahaska County sits in the Central time zone and is part of the Oskaloosa, IA Micropolitan Statistical Area.
Towns & Villages in Mahaska County
Mahaska County has 5 incorporated cities — Oskaloosa, New Sharon, Eddyville, Leighton and University Park — plus a long list of unincorporated crossroads, former coal-camp sites and rural communities. “Unincorp.” below marks places with no city government of their own; several are little more than a handful of houses at a township corner.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Oskaloosa | City · seat | Spring Creek | 11,558 | 52577 |
| New Sharon | City | Union | 1,262 | 50207 |
| Eddyville | City | West Des Moines | 970 | 52553 |
| Leighton | City | Prairie | — | 50143 |
| University Park | City | Spring Creek | — | 52577 |
| Barnes City | Unincorp. | Cedar | — | — |
| Beacon | Unincorp. | Union | — | — |
| Bellefountain | Unincorp. | Adams | — | — |
| Cedar | Unincorp. | Cedar | — | — |
| Cricket | Unincorp. | Harrison | — | — |
| Evans | Unincorp. | Union | — | — |
| Eveland | Unincorp. | Black Oak | — | — |
| Fremont | Unincorp. | Madison | — | — |
| Givin | Unincorp. | Jefferson | — | — |
| Indianapolis | Unincorp. | Garfield | — | — |
| Keomah Village | Unincorp. | Spring Creek | — | — |
| Lacey | Unincorp. | Lincoln | — | — |
| Lakonta | Unincorp. | East Des Moines | — | — |
| Lamson MH Park | Unincorp. | Spring Creek | — | — |
| Neska | Unincorp. | Monroe | — | — |
| Olivet | Unincorp. | Richland | — | — |
| Peoria | Unincorp. | Prairie | — | — |
| Rose Hill | Unincorp. | White Oak | — | — |
| Spring Valley | Unincorp. | Pleasant Grove | — | — |
| Taintor | Unincorp. | Scott | — | — |
| Tioga | Unincorp. | West Des Moines | — | — |
| Twin Pine MH Park | Unincorp. | Spring Creek | — | — |
| Union Mills | Unincorp. | Union | — | — |
| Wright | Unincorp. | Harrison | — | — |
Townships
Mahaska County is divided into 18 civil townships. The 2020 census did not break out population by township for this county, so counts below are marked unavailable rather than estimated.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Spring Creek | — | Oskaloosa, University Park |
| Union | — | New Sharon, Beacon |
| West Des Moines | — | Eddyville, Tioga |
| Prairie | — | Leighton, Peoria |
| Adams | — | Bellefountain |
| Black Oak | — | Eveland |
| Cedar | — | Cedar, Barnes City |
| East Des Moines | — | Lakonta |
| Garfield | — | Indianapolis |
| Harrison | — | Cricket, Wright |
| Jefferson | — | Givin |
| Lincoln | — | Lacey |
| Madison | — | Fremont |
| Monroe | — | Neska |
| Pleasant Grove | — | Spring Valley |
| Richland | — | Olivet |
| Scott | — | Taintor |
| White Oak | — | Rose Hill |
ZIP Codes
- 52577 — Oskaloosa (also serves University Park, Keomah Village and Lamson MH Park)
- 50207 — New Sharon (also serves Beacon and Union Mills)
- 52553 — Eddyville (also serves Tioga)
- 50143 — Leighton
The remaining rural crossroads and unincorporated communities use the ZIP code of their nearest post-office town rather than one of their own.
Geography
Mahaska County lies on the rolling till plains of south-central Iowa, drained by the South Skunk River in the north and Des Moines River tributaries along its western and southern edges. Cedar Creek and English Creek cut through the county’s farmland, which is dominated by corn and soybean production on deep prairie soils. Coal underlies much of the county’s southern half, a legacy of the deep-shaft mining era that built and then emptied towns such as Muchakinock and Buxton just outside the county line.
Mahaska County borders Poweshiek County to the north, Keokuk County to the east, Wapello and Monroe counties to the south, and Marion and Jasper counties to the west. Live pages currently exist for Monroe County, Marion County and Jasper County; Poweshiek, Keokuk and Wapello counties are named here without a link.
Demographics
Mahaska County’s population was 22,190 at the 2020 census, spread across 571 square miles of land for a density of roughly 39 people per square mile. Oskaloosa is by far the largest community at 11,558 residents, followed by New Sharon at 1,262. The county’s median household income runs below the Iowa median of $71,433, consistent with its farm- and manufacturing-based rural economy.
Economy & Local Life
Agriculture, food processing and light manufacturing anchor the county’s economy, alongside Oskaloosa’s role as a regional trade and medical hub for surrounding rural counties. William Penn University, a small private liberal-arts college, is based in Oskaloosa and is one of the county’s larger employers. The county fairgrounds and the historic downtown square in Oskaloosa — one of the largest of its kind in Iowa — host much of the county’s civic and social life through the year.
History
Mahaska County was organized on February 17, 1843, and takes its name from Chief Mahaska (also spelled Mahaskah) of the Iowa people. The county was among the first in Iowa to establish a sheriff and a justice of the peace. Coal mining shaped much of its later 19th- and early 20th-century history; Muchakinock, once one of Iowa’s largest coal camps, drew a large African American workforce recruited from the South before the mine closed and the community was largely abandoned by the 1920s.
Getting There
US Highway 63 runs north–south through the county, meeting Iowa Highways 92, 23, 146 and 149 near Oskaloosa. Approximate driving distances from Oskaloosa:
- Des Moines — 45 miles northwest
- Iowa City — 55 miles northeast
- Ottumwa — 25 miles south
- Pella — 20 miles west
The nearest commercial airport is Des Moines International Airport (DSM).
Frequently Asked Questions
Where is Mahaska County?
Mahaska County is in south-central Iowa, about 45 miles southeast of Des Moines.
What is the population of Mahaska County?
Mahaska County had a population of 22,190 at the 2020 census.
How big is Mahaska County?
The county covers 573 square miles (1,480 km2), of which 571 square miles is land.
What is the county seat of Mahaska County?
Oskaloosa is the county seat.
How many towns are in Mahaska County?
Mahaska County has 5 incorporated cities and around two dozen unincorporated communities across 18 townships.
What ZIP codes are in Mahaska County?
ZIP codes include 52577 (Oskaloosa), 50207 (New Sharon), 52553 (Eddyville) and 50143 (Leighton).
What is Mahaska County known for?
Mahaska County is known for its historic Oskaloosa town square and its 19th-century coal-mining history, including the coal camp of Muchakinock.
More counties in this state: Towns and villages in Iowa.