This is The Missouri & North Arkansas Railway's Bridge number 73.8 over the White River at Beaver, AR. The Bridge was numbered by its mileage from the railroad's western terminus at Joplin, MO. The tracks here, and all the others on the M&NA were finally abandoned in 1961, with the rails being pulled the following year. Beaver had a depot and an 18 car siding. Attached is a photograph taken from the locomotive of an eastbound train about to cross the bridge. The photograph appears to have been taken near the demise of the railroad. Hope this helps!