This extremely unique bridge is the 10th crossing of Mill Creek on the Union Pacific mainline.
Composed of a pair of identical trusses, the bridge likely has an interesting history.
The author has a theory that the current eastbound (unused) truss was part of the original bridge here, and the westbound span was added during double tracking in 1923.
The original location of this other truss cannot be confirmed, although it is likely that it came from another crossing of Mill Creek, likely closer to Alma.
It is also likely that the westbound truss has not changed, and the second truss was added to create a double track.
Regardless of the back story, the main spans feature 6-panel, riveted Warren Through Trusses. These spans are standardized in design, and can be seen in other places such as Iowa and Illinois.
The approach spans are both trestle and I-Beam. The Eastbound (I-Beam) approach was built in 1932.
In addition, the bridge rests on concrete substructures. However, the piers use two different types of concrete, indicating the second track was added without changing the original bridge.
While the westbound span is currently unused, it is still used for maintenance trucks. The deck remains in decent condition, despite the track being removed in 1981.
The author has ranked this structure as being regionally significant, due to the unique configuration of otherwise standardized trusses.
The bridge can be accessed from Exit #335 for I-70. The photo above is an overview.