Completed in 1977, New River Bridge is the world’s longest single-arch steel span bridge. Rising 876 feet above the river, it is America’s second-highest bridge. Its Cor-ten steel develops a light surface rust that prevents deeper rust, removes the need for paint, and gives the bridge a color that darkens over time. The concrete supports anchoring the bridge to the opposite slope required special engineering because abandoned mine tunnels honeycombing the hillside created a major problem. During construction, workers lowered the last beam to complete the arch, with steel brought into position by trolleys running on three-inch cables, and the new bridge towered high above its predecessor, Fayette Station Bridge.