Fort Morgan's Rainbow Arch Bridge has stood over the South Platte for a century

On the edge of Fort Morgan, a line of pale concrete arches curves up and over the South Platte River like a row of half-moons. This is the Rainbow Arch Bridge, and it has carried people across the water since 1923.

The design comes from Iowa engineer James B. Marsh, who patented his “rainbow arch” in 1912, blending steel and concrete so the arches rise above the deck instead of hiding beneath it. The Fort Morgan bridge is the only one of its kind in Colorado. By the accounts gathered by History Colorado, it stretched over 1,100 feet on eleven arches and was the longest rainbow arch in the world when it opened. It is now listed on the National Register of Historic Places and has been named a Colorado Civil Engineering Landmark.

Cars no longer cross it. Today the span is set aside for people on foot, which makes it an easy, photogenic stop. You can walk out over the middle, watch the river slide by below, and take in the arches framing the sky in both directions. It does not ask for much time, and it tends to surprise people who only know Fort Morgan as a dot off Interstate 76.

For the bridge’s history and current status, see the History Colorado listing for the Rainbow Arch Bridge.