GRAND RIVERS, Ky. (May 19, 2015) – 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 20, July 18 and Aug. 15, 2015, with tour start times of 9 a.m. and 11 p.m.