I hear that the replacement bridge was constructed in part due to the Meramec Basin Project, which called for construction of up to 30 or more dams throughout the Meramec River Watershed. Construction on one dam was underway when the project was cancelled but there were also plans to construct a dam above Union, MO, which would have backed up water under this very high bridge. The bridge seems a lot taller than is needed for this type of crossing.
Does anyone know about the history of the replacement structure?