Click the photo to view the full-size version
| Name | BNSF Prairie River Bridge Great Northern Railway Bridge #108.9 |
| Built By | Great Northern Railway |
| Currently Owned By | BNSF Railway |
| Superstructure Contractor | Unknown |
| Length | 305 Feet Total, 130 Foot Main Span |
| Width | 1 Track |
| Height Above Ground | 38 Feet |
| Superstructure Design | Warren Deck Truss, Deck Plate Girder and Steel Stringer |
| Substructure Design | Concrete and steel tower |
| Date Built | 1899, rebuilt 1929 |
| Traffic Count | 5 Trains/Day (Estimated) |
| Current Status | In Use |
| Great Northern Railway Bridge Number | 108.9 |
| Significance | Regional Significance |
| Documentation Date | 6/23/2015 |
In 1890, the Duluth and Winnipeg Railroad began construction on a new 85 mile railroad extending from Cloquet, Minnesota to Deer River, Minnesota. Construction was completed from Cloquet to Paupores in 1890, to Gunn in 1891, and to Deer River by 1892. In 1896, the D&W was sold to the Great Northern Railway (GN), which had built and acquired an extensive amount of railroad lines throughout Minnesota. The Eastern Railway Company of Minnesota would construct 99 additional miles from Deer River to Fosston, Minnesota in 1898; as well as an extension from Cloquet to Boylston, Wisconsin in 1899. The Eastern Railway Company would be purchased by the GN in 1907.
The GN operated this route as a mainline, as it connected to Seattle on the west, and the Twin Ports of Duluth, Minnesota and Superior, Wisconsin on the east. The line was critical for hauling iron ore, timber and agricultural commodities. In 1970, GN merged with rival Northern Pacific Railway and Chicago, Burlington & Quincy Railroad to form Burlington Northern Railroad. BN was in turn merged with Atchison, Topeka & Santa Fe Railway in 1996, to form BNSF Railway. BNSF currently operates the Cass Lake to Boylston segment of this line as the Lakes Subdivision.
Located along US Highway 2 east of Grand Rapids, this large deck truss bridge crosses the Prairie River. Originally built in 1899, the bridge featured a 130-foot 8-panel riveted Warren deck truss, approached by three 45-foot deck plate girder spans. In 1929, the bridge was rebuilt and a steel beam span added to each end. In addition, a third girder line was added to the girders, and a third truss line added to the truss. The bridge currently rests on concrete and steel tower substructures. The deck truss is a relatively early example of this design.
The strengthening technique of using additional girder/truss lines was commonly used by the Great Northern. This technique provided for a cost effective and long term solution to strengthening bridges. The additional lines could either be made from secondhand material from another bridge, or created new. It is currently unknown if the additional lines on this bridge were moved from another location. Overall, this bridge appears to be in fair to good condition, with the 1929 strengthening still holding up well. The author has ranked this bridge as being regionally significant, due to the unique strengthening of the bridge and the early age of the truss span.
Citations
| Build Date | Great Northern Mesabi Division Bridge Index, located at the Minnesota Historical Society |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |