Poweshiek is a county in Iowa, United States, on Interstate 80 midway between Des Moines and Iowa City. It had a population of 18,662 at the 2020 census and covers 586 square miles (1,520 km2) centred near 41°41′N 92°32′W.
Montezuma is the county seat, and its postal code is 50171. The county has seven incorporated cities, one census-designated place and a handful of unincorporated communities, all in the Central time zone.
Towns & Villages in Poweshiek County
Nine cities and one CDP carry their own 2020 census counts; the rest are unincorporated crossroads and rural clusters with no separate population figure. Grinnell, home to Grinnell College, is by far the largest place and sits outside the county seat itself.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Grinnell | City | Chester | 9,564 | 50112 |
| Brooklyn | City | Sugar Creek | 1,502 | 52211 |
| Montezuma | City · seat | Jackson | 1,442 | 50171 |
| Victor | City | Union | 875 | — |
| Holiday Lake | CDP | Pleasant | 473 | — |
| Malcom | City | Malcom | 270 | 50157 |
| Deep River | City | Deep River | 249 | 52222 |
| Barnes City | City | Grant | 156 | — |
| Searsboro | City | Warren | 129 | 50242 |
| Hartwick | City | Bear Creek | 92 | 52232 |
| Guernsey | City | Lincoln | 63 | 52221 |
| Ewart | Unincorp. | Scott | — | — |
| Newburg | Unincorp. | Madison | — | — |
| Oakland Acres | Unincorp. | Jefferson | — | — |
| Sheridan | Unincorp. | Sheridan | — | — |
Victor sits astride the Poweshiek–Iowa County–Tama County line and is often listed under the neighboring counties too; the population above is Victor’s combined city total. Barnes City is the smallest incorporated city in the county.
Townships
Poweshiek County has 16 civil townships. The county does not publish separate 2020 census counts for each township, so most populations below are unavailable; entries pair each township with its principal town where one exists.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Chester | — | Grinnell |
| Sugar Creek | — | Brooklyn |
| Jackson | — | Montezuma |
| Union | — | Victor |
| Pleasant | — | Holiday Lake |
| Malcom | — | Malcom |
| Deep River | — | Deep River |
| Grant | — | Barnes City |
| Warren | — | Searsboro |
| Bear Creek | — | Hartwick |
| Lincoln | — | Guernsey |
| Scott | — | Ewart |
| Madison | — | Newburg |
| Jefferson | — | Oakland Acres |
| Sheridan | — | Sheridan |
| Washington | — | Rural |
ZIP Codes
- 50112 — Grinnell
- 50171 — Montezuma
- 52211 — Brooklyn
- 50157 — Malcom
- 52222 — Deep River
- 52221 — Guernsey
- 50242 — Searsboro
- 52232 — Hartwick
Victor, Barnes City, Holiday Lake and the county’s smaller unincorporated places use ZIPs assigned to a neighboring post office rather than one of their own.
Geography
Poweshiek County sits in the south-central part of Iowa, on the rolling till plains drained by Deep River and the North Skunk River. Farmland covers most of the county; the small amount of surface water is concentrated around Diamond Lake and Rock Creek Lake, both state recreation areas near Montezuma.
It borders Tama County to the north, Iowa County to the east, Keokuk County to the southeast, Mahaska County to the south, and Jasper County to the west.
Demographics
The 2020 census counted 18,662 residents, down slightly from the 2010 figure. Grinnell (9,564) and Brooklyn (1,502) are the two largest communities, together holding well over half the county’s population. Median household income in Poweshiek County trends close to the Iowa median of $71,433, with Grinnell’s college-town economy pulling local figures somewhat higher than the rural townships. Overall density works out to about 32 people per square mile.
Economy & Local Life
Grinnell College, a private liberal-arts college founded in 1846, is the county’s largest single employer and shapes Grinnell’s economy along with several manufacturing plants on the city’s east side. Elsewhere the county is agricultural, with corn and soybeans dominating the township land outside the Interstate 80 corridor. Montezuma anchors county government and a smaller manufacturing base.
History
Poweshiek County was organized in 1843 and named for Meskwaki chief Poweshiek (1791–1854), who signed the 1832 treaty ending the Black Hawk War. The Poweshiek County Courthouse in Montezuma, completed in 1859, is listed on the National Register of Historic Places. Grinnell’s growth around its namesake college gave the county a second population center distinct from the seat almost from its founding.
Getting There
Interstate 80 crosses the county east–west, with exits serving Brooklyn, Grinnell and Malcom; U.S. Route 63 and Iowa Highway 146 provide north–south access.
- Des Moines — 55 miles west
- Iowa City — 45 miles east
- Newton — 20 miles west
- Oskaloosa — 30 miles south
The nearest commercial airport is Des Moines International Airport (DSM), about an hour’s drive from Montezuma.
Frequently Asked Questions
Where is Poweshiek County?
It is in Iowa, on Interstate 80 between Des Moines and Iowa City, in the south-central part of the state.
What is the population of Poweshiek County?
18,662 people, per the 2020 census.
How big is Poweshiek County?
586 square miles (1,520 km2).
What is the county seat of Poweshiek County?
Montezuma is the county seat.
How many towns are in Poweshiek County?
Ten incorporated cities and one census-designated place, plus several unincorporated communities.
What ZIP codes are in Poweshiek County?
Eight, led by 50112 (Grinnell) and 50171 (Montezuma).
What college is in Poweshiek County?
Grinnell College, a private liberal-arts college founded in 1846, is in Grinnell.
More counties in this state: Towns and villages in Iowa.