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| Name | CN Cloquet River Bridge |
| Built By | Duluth, Missabe & Northern Railway |
| Currently Owned By | Canadian National Railway |
| Superstructure Contractor | American Bridge Company of New York |
| Unknown | |
| Length | 435 Feet Total, 170 Foot Main Span |
| Width | 2 Tracks, 1 In Use |
| Height Above Ground | 25 Feet (Estimated) |
| Superstructure Design | Warren Deck Truss and Deck Plate Girder |
| Substructure Design | Steel Bent, Stone Masonry and Concrete |
| Date Built | 1906 (West Track) 1924 (East Track) |
| Traffic Count | 15 Trains/Day (Estimated) |
| Current Status | In Use |
| Significance | Moderate Significance |
| Documentation Date | 2/8/2014 |
In 1892, the Duluth, Missabe & Northern Railroad Company (DM&N) completed a 48 mile line extending from Stony Brook to Mountain Iron, Minnesota. The following year, an additional 31 miles between Duluth and Culver, Minnesota would be completed. It is believed that the connection between the two lines was also completed at this time. The DM&N would come under US Steel ownership in 1901, which operated the route to connect the iron ore from the iron rich areas around Mountain Iron to the ports at Duluth. The DM&N merged with the Duluth & Iron Range Railroad
to form the Duluth, Missabe & Iron Range Railway (DM&IR) in 1938. US Steel continued to control the DM&IR until 1988, when the railroad holdings of that company were sold to Blackstone Group. The railroad was in turn sold to Canadian National Railway in 2003. The route continues to be operated as the CN Missabe Subdivision.
Located near the ghost town of Burnett, this large truss and girder bridge crosses the Cloquet River alongside Center Line Road. The first bridge at this location was constructed in 1893, and likely consisted of a lightweight deck truss with lightweight deck plate girder approaches, set onto stone substructures. In 1906, a second track would be added to the west side of the bridge, utilizing a 170-foot 8-panel riveted Warren deck truss, approached by two deck plate girder spans on the south and three on the north. The substructures of the new portion utilized concrete and steel bents and towers. In 1924, the 1890s span was replaced with a span similar to the west track, and the stone piers rebuilt. Both tracks featured sheet metal decks, typical of bridges serving the iron range. Currently, only the eastern track of the bridge is in use.
Deck trusses are relatively uncommon in Minnesota, particularly in this area. While the two tracks look similar, there are numerous subtle differences between the spans. The lower chords and other members of the 1906 span utilize a traditional lacing and built up beams, while the members of the 1924 use a plate style lacing and solid beams. Railroads often double tracked bridges simply by adding an additional track to the bridge, as it was cheaper than constructing a brand new double track bridge. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked the bridge as being moderately significant, due to the truss design.
Citations
| Builder and build date | American Bridge Company plaques |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |