Rock Island Big Sioux River Bridge

Located near the Hilton Garden Inn in downtown Sioux Falls, this pony truss bridge carries a pedestrian walkway across the Big Sioux River. Little is known about the history of this bridge, although it is believed that the bridge was constructed of secondhand (relocated) parts. The bridge appears to have been constructed in approximately 1930, using two 60-foot riveted double intersection Warren pony truss spans and two 50-foot shallow deck plate girder spans. These spans are set onto concrete substructures, and the bridge has a slight curve at the south end. It is currently unknown where the spans may have been reused from. The two pony truss spans appear to have been fabricated in approximately 1885, and utilize a design commonly used by the Rock Island. These particular spans appear lighter and are considerably shorter than spans constructed in the late 1880s. The two deck plate girder spans are shallow design, and appear to have potentially been twinned. Railroads often reused steel and iron spans, as it was a cost effective way to replace bridges along branch lines. Often, when a span became unsuitable at one location, it could feasibly be reused at another location, with or without modifications. Overall, the bridge appears to be in good condition, with no significant deterioration noted. The bridge has been incorporated into a riverwalk area near the hotel. The author has ranked the bridge as being regionally significant, due to the truss design and possible old age.