Calhoun County is a county in Iowa, United States, in the central part of the state. It had a population of 9,927 at the 2020 census and covers 572 square miles (1,482 km2) centred near 42°23′N 94°39′W.
Rockwell City is the county seat, and its postal code is 50579. The county contains 12 incorporated cities and several unincorporated communities spread across 16 civil townships. Calhoun County observes Central time.
Towns & Villages in Calhoun County
The list below carries 21 named places: 12 incorporated cities — Rockwell City, the county seat, plus Lake City, Manson, Pomeroy, Farnhamville, Lohrville, Lytton, Somers, Knierim, Rinard, Jolley and Yetter — and 9 unincorporated communities with no city government of their own. “Twin Lakes Trailer Court” from older listings duplicates the unincorporated community of Twin Lakes and has been dropped.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Rockwell City | City · seat | 2,240 | 50579 |
| Lake City | City | 1,731 | 51449 |
| Manson | City | 1,709 | 50563 |
| Pomeroy | City | 526 | 50575 |
| Farnhamville | City | 383 | 50538 |
| Lohrville | City | 381 | 51453 |
| Lytton | City | 282 | 50561 |
| Somers | City | 128 | 50586 |
| Knierim | City | 53 | 50552 |
| Rinard | City | 38 | — |
| Jolley | City | 28 | 50551 |
| Yetter | City | 19 | — |
| Twin Lakes | Unincorp. | — | — |
| Knoke | Unincorp. | — | — |
| Lavinia | Unincorp. | — | — |
| Piper | Unincorp. | — | — |
| Rands | Unincorp. | — | — |
| Richard | Unincorp. | — | — |
| Sherwood | Unincorp. | — | — |
| Wightman | Unincorp. | — | — |
| Easley | Unincorp. | — | — |
ZIP Codes
- 50579 — Rockwell City
- 50563 — Manson
- 51449 — Lake City
- 50575 — Pomeroy
- 50538 — Farnhamville
- 50561 — Lytton
- 51453 — Lohrville
- 50586 — Somers
- 50551 — Jolley
- 50552 — Knierim (PO Box delivery)
Rinard and Yetter have no dedicated ZIP code of their own and are served by neighboring post offices.
Geography
Calhoun County sits in the north-central part of Iowa, on gently rolling till plains shaped by glaciation and given over almost entirely to row-crop farming. The North Raccoon River crosses the county, and the North and South Twin Lakes, a pair of natural glacial lakes near Lake City, are the county’s best-known water features and a state park draw. Of the county’s total area, 569.85 square miles is land and 2.27 square miles (0.4%) is water.
Calhoun County borders Pocahontas County to the north, Webster County to the east, Greene County to the southeast, Carroll County to the southwest and Sac County to the west.
Demographics
The 2020 census counted 9,927 residents in Calhoun County, for a density of roughly 17.4 people per square mile of land. Rockwell City (2,240) and Lake City (1,731) are the two largest communities, together holding about two-fifths of the county’s population. Household income in the county trends below the Iowa median of $71,433, consistent with a rural, agriculture-based economy.
Economy & Local Life
Agriculture is the backbone of the county’s economy, with corn, soybeans and hog production dominating the countryside. Rockwell City, the seat, is home to the county courthouse and county government offices, along with local schools serving the Southeast Valley and East Sac County districts that draw from the area. The Calhoun County Fair, held annually in Rockwell City, is the county’s signature community event.
History
Calhoun County was established from unorganized territory on January 15, 1851, and formally organized on November 7, 1855. It is named for John C. Calhoun, the seventh Vice President of the United States. The county’s most significant historical event is the F5 tornado that struck Pomeroy on July 6, 1893, destroying roughly 80% of the town’s buildings and killing 71 people — one of the deadliest tornadoes in Iowa history.
Getting There
Iowa Highway 4 runs north–south through Rockwell City and Lake City, linking the county to the wider state highway network. Approximate distances from Rockwell City:
- Fort Dodge — about 30 miles east
- Storm Lake — about 40 miles northwest
- Carroll — about 35 miles south
- Des Moines — about 90 miles southeast
The nearest larger commercial airport is Des Moines International Airport.
Frequently Asked Questions
Where is Calhoun County, Iowa?
It is in Iowa, in the north-central part of the state, centred near 42°23′N 94°39′W and bordered by Pocahontas, Webster, Greene, Carroll and Sac counties.
What is the population of Calhoun County?
9,927 residents at the 2020 census.
How big is Calhoun County?
572 square miles (1,482 km2), of which 569.85 square miles is land.
What is the Calhoun County seat?
Rockwell City is the county seat.
How many towns are in Calhoun County?
12 incorporated cities, plus about 9 unincorporated communities.
What ZIP codes are in Calhoun County?
Ten ZIP codes serve the county, from 50538 (Farnhamville) to 51453 (Lohrville); see the ZIP Codes section above.
What happened in Pomeroy in 1893?
An F5 tornado struck the town on July 6, 1893, destroying about 80% of its buildings and killing 71 people.
More counties in this state: Towns and villages in Iowa.