| Name | CPKC Straight River Bridge (Owatonna) Chicago & North Western Railway Bridge #M-216 |
| Built By | Chicago & North Western Railway |
| Currently Owned By | Canadian Pacific Kansas City Limited |
| Superstructure Contractor | American Bridge Company of New York |
| Substructure Contractor | Unknown (Abutments) Gaffin & Gehri of Fond du Lac, Wisconsin (Pier and Abutment Alterations) |
| Length | 124 Feet Total, 62 Foot Spans |
| Width | 1 Track |
| Height Above Ground | 30 Feet (Estimated) |
| Superstructure Design | Deck Plate Girder |
| Substructure Design | Stone Masonry and Concrete |
| Date Built | 1919 |
| Traffic Count | 5 Trains/Day (Estimated) |
| Current Status | Open to Traffic |
| Chicago & North Western Railway Bridge Number | M-216 |
| Significance | Local Significance |
| Documentation Date | 1/15/2012; 11/25/2017 |
Located in Owatonna, this large deck plate girder bridge carries the former Chicago & North Western Railway across the Straight River. The first bridge at this location was likely a timber pile trestle, constructed when the line was built. In 1879, the bridge would be replaced by an unknown bridge, set onto elongated stone abutments. In 1906, the bridge would be replaced by a secondhand 127-foot, riveted quadrangular lattice through truss span, fabricated in 1882 for use at an unknown location. When the truss span was installed, the original abutments were modified by using timber stringers over the parapet portion of the abutments. During the 1910s and 1920s, the C&NW invested significant capital into this route, replacing aging iron bridges with stronger steel structures. By 1919, the truss bridge had become too light for traffic, and it was decided to replace the bridge with a pair of 62-foot deck plate girder spans, set onto a new concrete pier and reusing the old stone abutments. The superstructure follows a standard design for the era, with two heavy plate girders and a ballast deck constructed of timber boards. The abutments of this bridge are an unusual stone parapet style, occasionally used where steep embankments were required. During the 1919 reconstruction, the original stone abutments were modified by using precast concrete ballast channels to replace the timber stringers. American Bridge Company fabricated the girders; Gaffin & Gehri constructed the concrete substructures and the stone substructures were constructed by an unknown contractor. Deck plate girder spans were commonly used by railroads, as they were durable and easy to construct. 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.
Citations
| Build date | Chicago & North Western Railway Valuation Notes at the Chicago & North Western Historical Society Archives |
| Builder (superstructure) | Missing American Bridge Company plaque |
| Builder (concrete substructures) | Janesville Weekly Gazette; June 27, 1919 |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |