Mason City Map
Mason City Information
Mason City
Mason City is a city and the county seat of Cerro Gordo County, Iowa, United States. The population was 27,338 in the 2020 census, a decline from 29,172 in the 2000 census. The Mason City Micropolitan Statistical Area includes all of Cerro Gordo and Worth counties. It is commonly referred to as the "River City", as the city grew up centered on the Winnebago River.