Located in Rapid City, this unique through girder has a long history, tracing back many years and covering two states.
The original bridge at this location was a wooden trestle. However, by 1935, it was desirable to replace this trestle with a bridge of permanent construction.
The chosen solution was to use two spans located at the Tomah, Wisconsin bridge yard. Originally built 1887 as a three span bridge across the Kishwaukee River at Bridge #Z-204 east of Genoa, Illinois; that bridge was replaced in 1931, and the old girders saved for future reuse.
One such span was reused as a deck girder at Canton, South Dakota; where it was destroyed in a 2019 ice jam. The other two spans remained in storage, until a possible reuse was discovered.
In December 1935, plans began to replace the original bridge at this location. As a result, two 72-foot spans from Z-204 would be remodeled and reused here the following year. As part of the remodeling, the spans were converted from double track to single track, likely altering the entire floor system.
Bridge #Z-204; Genoa, Illinois. From Annual report of the Railroad and Warehouse Commission of the State of Illinois, 1899.
While relocating spans is rather common, it is unusual to convert a two track through girder span to a single track span. Unfortunately, the author was not able to get underneath the bridge, to look for signs of modification.
Overall, the bridge remains in good condition. The bridge has an unknown future, as Rapid Creek is particularly notorious for flooding. However, it is believed that the RWRR will eventually reopen this line for freight traffic.
The author has ranked this bridge as being moderately significant, due to the common design.
The photo above is an overview. The bridge is easily accessible nearby trails.