Earl Keeler, 91, (right) retired U.S. Army Corps of Engineers Nashville District lock operator, points to the building at the 100-year-old Hales Bar Dam site where he worked from 1960 until its closing in 1967. At left is the just recently retired Nickajack Lock lockmaster, Butch Witcher, who Keeler helped train at Nickajack Lock in 1980. Witcher arranged the Dec. 19, 2013 visit for his mentor and old friend.