The alignment had curved within sight of Union Dam. The dam had been
disused for at least 20 years when, in 1972, floods from Tropical
Storm Agnes breached it and carved out the route around it seen here.
Over subsequent years, the river washed away so much of the bank that
stone-in-wire-mesh cages seen at the bottom were dropped along the
shoreline to reduce erosion. The stone has obscured any surviving
stringers in this spot.
The original dam near this location was built by the Union Manufacturing
Company about 1808. The company's founder, William Patterson, for whom
the Patterson Viaduct is named, would later become a director of the B&O.
A successor company, WJ Dickey, built the concrete dam seen here