The Brownson Viaduct was designed by Nebraska's Department of Roads and Irrigation to provide access to the Sioux Ordnance Plant in June 1942, in the midst of World War II. Its construction was immediately advertised for bids under Project No. DA-WI-2(1), and on June 25, 1942, a contract was awarded to the Bushman Construction Company of Saint Joseph, Missouri (cost: $30,927.45). In the months prior to the bridge's construction, the American Association of State Highway Officials, Committee on Standards, in conjunction with the War Department, had developed a "Priorities Critical List regarding materials deemed essential to the war effort. The Brownson Viaduct indicated this effort to save critical materials, most notably steel, and was built as a 13-span, treated timber trestle with an overall length of 352 feet. Other than the steel fasteners and concrete pedestals for the piers and abutments, the structure was built entirely of wood, including a laminated wood deck (which has subsequently been paved with asphalt). Since its completion in the fall of 1942, the overpass has carried vehicular traffic, with paving of the deck with asphalt as the only alteration of note. d. - NRHP, May 6 1992