[2] Platted in 1855, Mason City is a commercial and industrial center for north central Iowa.

Central Park, a public square, was part of the city's original plat and is the contributing site.

They include Parker's Opera House (1883) by William Foster, the former Mason City Public Library (1904) by Patton & Miller, the Park Inn Hotel (1909) and the City National Bank (1910) by Frank Lloyd Wright, First National Bank (1911) by Liebbe, Nourse & Rasmussen, the MBA Building (1917) by Bell & Bentley, the Hanford Hotel (1921) by Proudfoot, Bird & Rawson, the YMCA (1926) by Tyrie and Chapman, and the former First Church of Christ, Scientist (1928) by Clyde W. Smith.

[2] An apartment building, The Kirk (1903), destroyed by fire in 2023,[3] is also individually listed on the National Register.

Media related to Mason City Downtown Historic District at Wikimedia Commons