Cerro Gordo County is a county in Iowa, United States, in the north-central part of the state, home to Clear Lake, one of Iowa’s largest natural lakes. It had a population of 43,127 at the 2020 census and covers 575 square miles (1,490 km2) centred near 43°04′46″N 93°16′01″W.
Mason City is the county seat, and its postal code is 50401. The county has 9 incorporated cities, 2 census-designated places, and a handful of unincorporated communities, spread across 16 civil townships. Cerro Gordo County observes Central time and carries Iowa county number 17.
Towns & Villages in Cerro Gordo County
Cerro Gordo County’s population is concentrated around Mason City and the resort town of Clear Lake, on the lake of the same name. The table below lists every incorporated city, the two census-designated places (CDP), and the unincorporated communities and rural subdivisions carried in county records. "City · seat" marks the county seat; "Unincorp." covers places with no municipal government.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Mason City | City · seat | Mason | 27,338 | 50401 |
| Clear Lake | City | Clear Lake | 7,687 | 50428 |
| Nora Springs | City | Union | 1,369 | — |
| Rockwell | City | Grant | 1,071 | 50469 |
| Ventura | City | Lake | 711 | 50482 |
| Thornton | City | Grimes | 400 | 50479 |
| Plymouth | City | Bath | 375 | 50464 |
| Meservey | City | Geneseo | 222 | 50457 |
| Rock Falls | City | Falls | 150 | 50467 |
| Swaledale | City | Mount Vernon | 144 | 50477 |
| Dougherty | City | Dougherty | 62 | 50433 |
| Burchinal | CDP | Mason | 33 | — |
| Portland | CDP | Portland | 28 | — |
| Owen | Unincorp. | Owen | — | — |
| Hanford | Unincorp. | Lincoln | — | — |
| Cartersville | Unincorp. | Pleasant Valley | — | — |
| Cameron | Unincorp. | Lime Creek | — | — |
| Emery | Unincorp. | Geneseo | — | — |
| Freeman | Unincorp. | — | — | — |
| Hurley | Unincorp. | — | — | — |
| Mason City Junction | Unincorp. | Mason | — | — |
| Wheelerwood | Unincorp. | — | — | — |
| Plymouth Junction | Unincorp. | Bath | — | — |
| Central Heights | Unincorp. | Mason | — | — |
| Ventura Heights | Unincorp. | Lake | — | — |
| Green Meadows MH Park | Unincorp. | Clear Lake | — | — |
| Lakeside Acres Mobile Park | Unincorp. | Clear Lake | — | — |
| Orchard Park MH Court | Unincorp. | Clear Lake | — | — |
| Registry Park | Unincorp. | Clear Lake | — | — |
Several of the smallest entries — Green Meadows, Lakeside Acres, Orchard Park and Registry Park — are manufactured-home communities clustered around Clear Lake rather than platted towns; they carry no ZIP of their own and are served by Clear Lake’s 50428.
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Mason | — | Mason City, Mason City Junction, Central Heights |
| Clear Lake | — | Clear Lake and its lakeshore MH communities |
| Lake | — | Ventura, Ventura Heights |
| Grant | — | Rockwell |
| Union | — | Nora Springs |
| Grimes | — | Thornton |
| Bath | — | Plymouth, Plymouth Junction |
| Geneseo | — | Meservey, Emery |
| Falls | — | Rock Falls |
| Mount Vernon | — | Swaledale |
| Dougherty | — | Dougherty |
| Portland | — | Portland |
| Owen | — | Owen |
| Lincoln | — | Hanford, rural farmland |
| Pleasant Valley | — | Cartersville, rural farmland |
| Lime Creek | — | Cameron, rural farmland |
ZIP Codes
- 50401 — Mason City (also serves Mason City Junction, Central Heights)
- 50402 — Mason City (PO Box only)
- 50428 — Clear Lake (also serves the lakeshore MH communities)
- 50469 — Rockwell
- 50482 — Ventura, Ventura Heights
- 50464 — Plymouth, Plymouth Junction
- 50479 — Thornton
- 50457 — Meservey, Emery
- 50477 — Swaledale
- 50433 — Dougherty
- 50467 — Rock Falls
Nora Springs, Burchinal, Portland, Owen, Hanford, Cartersville, Cameron, Freeman, Hurley and Wheelerwood have no confirmed ZIP of their own and are covered by a neighboring post office’s code.
Geography
Cerro Gordo County sits on the Iowan Surface, a gently rolling glacial plain drained by the Winnebago River and the West Fork Cedar River, with Clear Lake — the state’s fourth-largest natural lake — forming the county’s most prominent water feature in its southwest corner. The county borders Winnebago County to the north, Worth County to the northeast, Mitchell County to the east, Floyd County to the southeast, Butler County to the south, Franklin County to the southwest, Wright County to the west, and Hancock County to the northwest.
Demographics
Cerro Gordo County had 43,127 residents at the 2020 census, a density of about 76 people per square mile. Mason City (27,338) and Clear Lake (7,687) together hold roughly four in five county residents. Median household income runs below the Iowa median of $71,433, reflecting Mason City’s older industrial-era housing stock relative to faster-growing metro counties.
Economy & Local Life
Mason City anchors the county’s economy as a regional health-care and retail hub for north-central Iowa, home to MercyOne North Iowa Medical Center and North Iowa Area Community College. Manufacturing remains significant, carrying on the city’s cement- and brick-making heritage. Clear Lake’s economy runs on lake tourism — boating, fishing and the historic Surf Ballroom, which draws visitors each summer for its concert season and the annual Winter Dance Party tribute to Buddy Holly, Ritchie Valens and the Big Bopper, who died in a plane crash near the town in 1959.
History
Cerro Gordo County was organized in 1851 and named for the Battle of Cerro Gordo, an 1847 engagement of the Mexican–American War. Mason City grew around a 19th-century sawmill and dam site on Willow Creek before becoming a railroad and cement-manufacturing center; architect Frank Lloyd Wright designed the Historic Park Inn Hotel there, one of the last surviving Prairie School hotels he built.
Getting There
- Charles City — 24 miles southeast
- Osage — 22 miles east
- Britt — 25 miles northwest
- Hampton — 25 miles south
Interstate 35 crosses the county’s west side, with US Routes 18 and 65 and Iowa Highways 27 and 122 serving Mason City directly. Mason City Municipal Airport offers regional service; the nearest larger commercial airport is Des Moines International, about 120 miles south.
Frequently Asked Questions
Where is Cerro Gordo County?
It is in north-central Iowa, on the Winnebago and West Fork Cedar Rivers, about 120 miles north of Des Moines.
What is the population of Cerro Gordo County?
43,127 at the 2020 census.
How big is Cerro Gordo County?
575 square miles (1,490 km2), including 6.8 square miles of water — most of it Clear Lake.
What is the Cerro Gordo County seat?
Mason City is the county seat.
How many towns are in Cerro Gordo County?
Nine incorporated cities, two census-designated places, and several unincorporated communities.
What ZIP codes are in Cerro Gordo County?
Eleven codes, from 50401 in Mason City to 50482 in Ventura; see the ZIP Codes section above.
Why is Clear Lake famous?
Its Surf Ballroom hosted the last concert of Buddy Holly, Ritchie Valens and the Big Bopper on February 2, 1959, the night of their fatal plane crash nearby.
More counties in this state: Towns and villages in Iowa.