Up until their remodel, my folks had paneling on their kitchen walls that featured drawn pictures of different buildings, and two bridges--a covered one shown in portal, and the other was an elevation of this identical bridge design, right down to the rectangular insets stamped into the arches! Almost makes me wonder if this particular bridge was the model for that paneling pic?
After some searching, I discovered that this bridge is a rare Marsh Rainbow Arch!
This is the only rainbow arch in Illinois