1922 Rainbow Bridge over South Platte River at Fort Morgan, CO

(Bridge Hunter broke Mar 22, 2023; no Historic Bridges; Satellite)

Street View, Jun 2023

John Weeks posted eight photos with the comment:

I came across a really nice historic bridge while out on a run in Fort Morgan, Colorado. This is the Rainbow Bridge. It was built in 1922, but bypassed with a new highway in 1963. A flood in 1965 destroyed the new bridge, so the historic Rainbow Bridge had one last hurrah before being converted into a pedestrian bridge.

A rainbow arch is a somewhat unusual method of construction. Normally, the roadway is either above or below the arch, but in a rainbow arch, the roadway goes through the middle of the arch. There are 2 such bridges that I know of in Minnesota, both about the same age as this example.

Even more unusual is that there are multiple arches that make up the bridge, 11 in all. Most rainbow arch bridges have only a single span. This bridge was the longest rainbow arch bridge in the world when it was built.

The city of Fort Morgan has developed trails on both sides of the Platte River, with this bridge connecting the two trail systems. That gives the bridge a real purpose given that the highway bridge is too narrow for pedestrians or bikes.