Hi-Line Railroad Bridge

Located on the north side of Valley City, this landmark viaduct carries the BNSF Railway (former Northern Pacific Railway) across the Sheyenne River Valley. The original NP line through Valley City involved steep grades and sharp curves. By 1906, the NP sought to construct a new "high line" around Valley City, including a large viaduct over the Sheyenne River. The new line would leave the original alignment near 121st Avenue east of Valley City, and join the original alignment near 114th Avenue, west of Valley City. Construction on the new alignment and viaduct began in 1906, and would be completed in 1908.

The viaduct across the Sheyenne River Valley crossed the river, a Soo Line Railroad mainline, and 117th Avenue; and would be constructed of 61 deck plate girder spans, set onto large steel towers and concrete substructures. The viaduct utilized 75-foot spans, with 45-foot spans set onto the steel towers, a 60-foot span on the west end (span #3), and 101-foot spans across the Sheyenne River and the Soo Line. While the bridge was originally constructed for one track, the steel towers were built wide enough to add a second track if necessary. This second track was never added to the bridge. On the east end of the bridge, 11 timber trestle spans originally approached the deck plate girders. However, these spans were replaced in approximately 1980 with a pair of 40-foot deck plate girder spans, reused from an unknown location. New steel pile substructures were constructed for these spans. It is likely that the east approach was reconstructed to address issues with erosion, which was common for large viaducts such as this. Railroads often reused spans to save on costs for repairing and reconstructing bridges. Often, when a steel span became inadequate or unneeded at one location, it could feasibly be reused at another location. It appears the eastern spans were added during the Burlington Northern era, so it is unknown where the spans may have come from or which railroad may have originally constructed them.

Deck plate girder viaducts were used by railroads to cross large valleys, as this particular viaduct design was more cost effective than large embankments or truss viaducts. Two other large viaducts are still in use in North Dakota, including the Gassman Coulee Viaduct near Minot; and the Karnak Bridge, located approximately 30 miles upstream. Of the three large viaducts in North Dakota, this bridge is the longest, at nearly 3/4 of a mile. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being highly significant, due to the large scale design, and landmark status in North Dakota.