Snider Bridge
220th St. over unnamed stream, Corning, IAThe Snider Bridge carries a gravel-surfaced county road over a small stream some four miles west of Corning. This medium-span pony truss dates to 1885. In June of that year ti Adams County Board of Supervisors received petitions for seventeen small bridges. The largest of these proposed bridges was requested by George Snider, who asked that a 60-foot bridge be built in the west part of Section 31 of Quincy Township. Viewing a number of the petitions favorably, the board immediately began formulating construction plans. For the two longest spans, including the Snider Bridge, the board decided to solicit bids to erect iron structures. On June 15th bids were received from eight firms, and a contract to build both bridges was awarded to Reeve, Ward and Keepers of Clinton, Iowa. The contract price for both crossings was $1451.00. Completed later that year, the Snider Bridge has carried wagon and auto traffic since. The sub-structure and approach spans have been replaced entirely, but the pinned Pratt truss remains in unaltered condition.
The bowstring arch-truss was the iron bridge of choice for short-to medium-span applications in Iowa in the 1860s and 1870s. By 1880, the pin-connected Pratt truss had begun to supersede the bowstring for roadway bridges. Patented in 1844 by Thomas and Caleb Pratt, the design is distinguished by vertical members acting in compression and diagonals that act in tension. "The Pratt truss is the type most commonly used in America for spans under two hundred and fifty (250) feet in length," noted bridge engineer J.A.L. Waddell wrote in 1916. "Its advantages are simplicity, the economy of metal, and suitability for connecting to the floor and lateral systems." Virtually all of the major regional bridge fabricators manufactured Pratt trusses and marketed them extensively to Iowa's counties. This included the fledgling Clinton, Iowa, the firm of Reeve, Ward and Keepers. Thousands of pinned Pratt trusses were erected throughout Iowa, in both through and pony configurations, and many remain in service today. The Snider Bridge is distinguished as among the earliest of the Pratt pony trusses remaining in the state. The oldest remaining roadway bridge in Adams County, it is further distinguished as the earliest truss in the state attributable to this obscure Iowa firm. In well preserved condition, the Snider Bridge is an important early resource of Iowa transportation.
Listed in National Register of Historic Places in 1998.
The National Register of Historic Places is the official list of the Nation’s historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Park Service’s National Register of Historic Places is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America’s historic and archeological resources.