Did you know the Cotter Bridge is the longest concrete rainbow bridge in the US? Rainbow bridges are so named because of the beautiful rainbow shape of the arches. The bridge was designed by James Marsh who pioneered the use of the majestic rainbow concrete arch bridges. It was open in 1930 with the offical name of R.M. Ruthven Bridge (Mr. Ruthven was the County Judge at the time). If you are a history buff, check out this article: https://ascelibrary.org/doi/pdf/10.1061/ciegag.0001119
