The Nicollet County Historical Society was organized on August 22, 1928. From its home in the Treaty Site History Center, the Nicollet County Historical Society preserves, protects, and interprets the history of Nicollet County and the state of Minnesota. The Treaty Site History Center features a nationally recognized award-winning exhibit on the Traverse des Sioux Treaty of 1851 and its consequences, other local history displays, and a full-service research archive.