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. History The region around what would later be first called Shibboleth was a summer home to the Sioux and Winnebago nations. The first settlement that became Shibboleth was established in 1853 at the confluence of the Winnebago River and Calmus Creek. The town had several names: Shibboleth, Masonic Grove, and Masonville until Mason City was adopted in 1855, in honor of a founder's son, Mason Long. In 1854, John McMillin opened the first store, and Dr. Silas Card opened the first medical practice in the area. Lizzie Thompson established the first schoolhouse in a log cabin in 1856. The United States Post Office Department started service to the town in 1857. Mason City was named the county seat in 1858. In 1870, Mason City, Iowa was officially incorporated as a town with Darius B. Mason as the first mayor. Musical heritage Mason City is known for its musical heritage, consistently producing successful performers and educators. The city's "favorite son," Meredith Willson, grew up in Mason City and played in the Mason City Symphonic Band as a high school student. Willson's crowning achievement was the famous stage musical The Music Man. Many of the characters in it were based on people Willson knew from his childhood in Mason City. And it also features the Parker's Opera House. Geography According to the United States Census Bureau, the city has a total area of , of which is land and is water. Climate Mason City has a warm-summer humid continental climate (Köppen: Dfb), bordering closely on the hot-summer variant. Demographics 2010 census As of the census of 2010, there were 28,079 people, 12,366 households, and 7,210 families living in the city. The population density was . There were 13,352 housing units at an average density of . The racial makeup of the city was 93.8% White, 1.8% African American, 0.3% Native American, 0.9% Asian, 1.3% from other races, and 1.9% from two or more races. Hispanic or Latino of any race were 5.1% of the population. There were