This bridge has one of the longest spans in America. There are no supports in the river, because of freezing and the ice breaking up would crash into its supports. It has some kind of rollers for expansion because of freezing.
The bridge was built in the lower 48 and shipped to Nenana, then assembled on the ice in 1923. Upon completion President Harding tapped a gold spike into the rails on the far side.
I wonder if it is still there?