On Thursday, June 27, Lower Monumental Lock and Dam is celebrating the 50th anniversary of its construction with a commemoration event beginning at 9 a.m. with an open house from 9 a.m. to 10:00 a.m. and a ceremony from 10:15 a.m. to 11:00 a.m. The public is invited to the day’s festivities marking U.S. Army Corps of Engineers efforts to build the dam, navigation lock, powerhouse, fish ladders and recreation areas. The keynote speaker will be Lt. Col. Christian N. Dietz, Walla Walla District Commander.