The photo above is an aerial view of Monongahela River Locks and Dam 4 near Charleroi, Pennsylvania, July 21, 2023. The facility is one of nine navigation structures on the Monongahela River that provide navigation from Fairmont, West Virginia, to downtown Pittsburgh. The U.S. Army Corps of Engineers started constructing the lock at Charleroi in 1931 and finished in 1932. The project became operational Aug. 14, 1932. The most recent construction at the facility began in 1994 to replace the main chamber with a new lock measuring 720 feet long and 84 feet wide. Charleroi is located at river mile 41.5. Pittsburgh District’s 26,000 square miles include portions of western Pennsylvania, northern West Virginia, eastern Ohio, western Maryland, and southwestern New York. It has more than 328 miles of navigable waterways, 23 navigation locks and dams, 16 multi-purpose flood-control reservoirs, 42 local flood-protection projects, and other projects to protect and enhance the nation’s water resources infrastructure and environment. (U.S. Army Corps of Engineers Pittsburgh District photo by Michel Sauret)