The Boone County Historical Center is a historic building in Boone, Iowa. Constructed in 1907 as the Champlin Memorial Masonic Temple, the building housed Mt. Olive Lodge No. 79 (a local chapter of the Freemasons) until 1990 (when the lodge moved to a new building). It now houses the Boone County Historical Society. It was listed on the National Register of Historic Places in 1990.