Mason City Chamber of Commerce Loading Map.... Mason City Chamber of Commerce9 N Federal Ave. - Mason CityEvents 43.1521935 -93.20077989999999 Address 9 N Federal Ave. Mason City IA Cerro Gordo 50401 United States Upcoming Events No events in this location mariekboyd2018-10-07T00:59:18-05:00October 7th, 2018| Share This Story, Choose Your Platform! FacebookXRedditLinkedInTumblrPinterestVkEmail