Dakota, and Interstate 90 crosses the reservoir between Chamberlain and Oacoma. See also List of lakes in South Dakota External links U.S. Army Corps of Engineers - Fort Randall Project Lake Francis Case Map, U.S. Army Corps of Engineers References Francis Case Francis Case Chamberlain, South Dakota Protected areas of Brule County, South Dakota Protected areas of Charles Mix County, South Dakota Protected areas of Gregory County, South Dakota Protected areas of Lyman County, South Dakota Bodies of water of Brule County, South Dakota Bodies of water of Charles Mix County, South Dakota Bodies of water of Gregory County, South Dakota Bodies of water of Lyman County, South Dakota