BNSF Rum River Bridge

Located in Anoka, this deck plate girder bridge carries the former Great Northern Railway and Northern Pacific Railway over the Rum River. A crossing has existed at this location since 1864, when a timber bridge was constructed during the initial construction of this line. This bridge was replaced by a timber truss bridge in 1867, which was located slightly downstream from the first bridge. The bridge is believed to have been replaced again in the 1870s. 1884, the NP constructed a second parallel bridge north of the GN bridge, which consisted of two 160-foot, pin-connected iron through truss spans, set onto stone abutments and a stone pier. It is believed that the GN reconstructed their bridge in 1893, using four 83-foot deck plate girder spans, set onto stone piers.

By 1905, the twin truss bridges had become too light for traffic, and the railroads coordinated to raise their tracks and construct new heavier bridges. The current bridges were constructed in 1905, and consists of four deck plate girders each. The NP used four 80-foot deck plate girder spans, set onto two new concrete piers, the original stone pier and the original stone abutments. The GN used four 83-foot deck plate girder spans, set onto the previous stone piers and abutments. The girders are nearly identical, and use a standard design for the era. An unknown contractor fabricated the steel, and unknown contractors constructed the substructures at various times. It is believed that the old bridge spans were used throughout the NP and GN systems. This type of bridge was commonly used throughout the United States, due to the ease of construction and durability. The center piers of this bridge were apparently replaced at some point, possibly in the 1980s or 1990s. It is possible that the original stone center piers had begun to fail. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being locally significant, due to the common design.