The Mason City Area Office does not serve all of Hardin county. For if you live east of Highway 65 and do not live in Iowa Falls, see Waterloo Area Office. It also manages the Decorah Branch Office and the North Iowa Area Community College Service Unit. If you have any questions or concerns, please contact the Area Office Supervisor, Brian Warner. Address 600 South Pierce Ave. Mason City, IA 50401 United States Phone Number (641) 422-1551 Fax Number (641) 422-1565 Counties Served Allamakee Cerro Gordo Floyd Franklin Hancock Hardin (West) Howard Mitchell Winnebago Winneshiek Worth Email Office