MAHONING LAKE –In 1941, 75 years ago, the U.S. Army Corps of Engineers completed Mahoning Dam and placed it into operation. Since, that time Mahoning Dam has been providing flood protection for the lower Allegheny River Valley and the upper Ohio River. In commemoration of this major accomplishment, Mahoning Creek Lake will hold a 75th Anniversary celebration from 11 a.m. – 3 p.m. on Saturday, June 18.