Chicago & North Western Railway Bridge #W-724

Located east of Poplar Grove, this small steel stringer bridge carries the former Chicago & North Western Railway KD Line over an unnamed ditch. The first bridge at this location was likely a timber pile trestle. In the late 1890s and early 1900s, the C&NW invested some capital into this line, replacing deteriorated timber bridges with new stone and steel structures. In 1907, new stone abutments were constructed, and in 1908, the present superstructure was installed. Currently, the bridge consists of a 16-foot steel stringer span, set onto stone abutments. The superstructure uses an unusual design, consisting of several steel stringers placed equidistant. A steel channel ballast deck is installed above the beams, giving the structure a similar function to a culvert. The substructures uses a standard design, with stepped wing walls extending diagonally from the bridge. American Bridge Company fabricated the superstructure at their Lassig Plant in Chicago, and an unknown contractor constructed the abutments using stone quarried at an unknown location. Steel stringer spans were popular for railroad use, as they were durable and easy to construct. This particular design was used at a handful of locations along the C&NW system, but was more popular later in the 20th Century. Since the initial construction, the bridge has seen few alterations. It currently carries the Long Prairie Trail, and wooden handrails and decking have been added to the structure. Overall, the bridge appears to be in fair condition, with deterioration noted mainly to the timber bearing blocks. Boone County plans to replace most of the original railroad structures along the Long Prairie Trail, and funding has been awarded to replace this bridge in the upcoming years. The author has ranked this bridge as being locally significant, due to the common design.