National Register of Historical Places - Clarke County - Provides a listing of properties, districts, and landmarks in the county. Includes architectural style and period of significance. - http://www.historicdistricts.com/IA/Clarke/state.html
Clarke County Historical Society - Established in 1971 for the purpose of preserving local history through articles, documents, books, and family records. Includes a meeting schedule, membership details, an officers list, museum complex information and hours. Located in Osceola. - http://www.rootsweb.com/~iaclarke/hissoc.html