Rainbow Arch Bridge - Cotter, Arkansas - American Guide Series on Waymarking.com

The Cotter Bridge was constructed during the Arkansas Highway and Transportation Department Era: 1923-1939 historic context, and is an outstanding and unique Arkansas example of a reinforced-concrete Rainbow Arch bridge type. Completed in 1930, the Cotter Bridge is significant as the only bridge in Arkansas known to be designed and engineered by the Marsh Engineering Company of Des Moines, Iowa. The Marsh Company is well known for its Rainbow Arch bridge, a design patented in 1912 by James Barney Marsh, the company's founder. The bridge is an excellent example of the Marsh Rainbow Arch construction technique, where the steel arches were assembled on the ground and then lifted into place on the piers. These steel arches supported their own framework while the concrete was cast around them, thus eliminating the need for building costly and time-consuming falsework beneath the structure. The Cotter Bridge was uniquely constructed in that a cableway, suspended across the river, was used to transport all the necessary materials and tools out to the various parts of the bridge. Due to its strategic location on the only east-west route in northern Arkansas, the Cotter Bridge was instrumental in opening up a new region of the Ozarks. which was to become a major reason and recreation area in the United States. The Cotter Bridge became Arkansas' first National Civil Engineering Landmark in 1986. As such, the Cotter Bridge is eligible under Criteria A and C with national significance.