GRAND RIVERS, Ky. (May 16, 2014) – The U.S. Army Corps of Engineers Nashville District is offering the public free guided tours of Lake Barkley’s Powerhouse, Lock and Natural Resource Management Office. Approximately two hours in length, tours are scheduled June 21, July 19 and Aug. 16, 2014, with tour start times of 9 a.m., 11 a.m., and 2 p.m.