Bethany Bridge is a green truss bridge that crosses the Allatoona Creek arm of Lake Allatoona, just south of where it meets the Etowah River arm. The bridge carries Red Top Mountain Road, and connects Red Top Mountain State Park to nearby Interstate 75 and U.S. 41 (Joe Frank Harris Parkway). It was opened in 1950, when the lake began to fill after construction of Allatoona Dam.