DAIR Big Sioux River Bridge (Oak Ridge)

Fairview, Lincoln County, South Dakota

To

Rock Valley, Sioux County, Iowa

Default pic
Overview
Overview
North approach
North approach
Main span
North pier
Lower angle connection
Lower connection
Middle pier
North approach
Upper angle connection
Upper connection
Looking north
Looking north
South abutment
Overview
Main span
Girder span
South approach
Middle pier
Main span
North approach
Overview
Overview
Looking north
North abutment
Looking south
Looking south

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Default Pic
Overview
Overview
North approach
North approach
Main span
North pier
Lower angle connection
Lower connection
Middle pier
North approach
Upper angle connection
Upper connection
Looking north
Looking north
South abutment
Overview
Main span
Girder span
South approach
Middle pier
Main span
North approach
Overview
Overview
Looking north
North abutment
Looking south
Looking south
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Date Taken:
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Caption:
Name DAIR Big Sioux River Bridge (Oak Ridge)
Chicago, Milwaukee & St. Paul Railway Bridge #T-598
Built By Chicago, Milwaukee, St. Paul & Pacific Railroad
Currently Owned By D&I Railroad
Superstructure Contractor Lassig Bridge & Iron Works of Chicago (Truss)
Wisconsin Bridge & Iron Company of North Milwaukee, Wisconsin (Girder)
Length 802 Feet Total, 123 Foot Main Span
Width 1 Track
Height Above Ground 25 Feet (Estimated)
Superstructure Design Pratt Pony Truss, Deck Plate Girder and Timber Pile Trestle
Substructure Design Timber Pile and Steel Pile
Date Fabricated 1900 (Truss)
1932 (Girder)
Date Built 1932
Original Locations Bridge #Z-1534; Neola, Iowa (Truss)
Bridge #I-794; Elmira, Missouri (Girder)
Traffic Count 2 Trains/Day (Estimated)
Current Status In Use
Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge Number T-598
Significance Regional Significance
Documentation Date 12/30/2014

In 1878, the Sioux City and Pembina Railway (SC&P) began construction on a line extending from Elk Point, South Dakota to Sioux Falls, South Dakota.  Concurrently, the Southern Minnesota Railway (SM) began construction on a line extending from Egan, South Dakota to Sioux Falls.  In 1879, the SC&P merged with the Dakota Southern Railroad to form the Sioux City & Dakota Railroad (SC&D).  In 1880, the SM would be conveyed to the Chicago, Milwaukee & St. Paul Railway, and in 1881 the SC&D would be acquired by the same company.  Work was quickly completed on the line.  Known as the Milwaukee Road, the railroad had constructed a significant network of lines throughout the Midwest, connecting several states with Chicago. 

The Milwaukee Road operated this route as a secondary route, connecting cities and other lines in South Dakota. The Milwaukee Road was often in financial trouble, especially after the costly Pacific Extension was completed in 1909. In 1925, the company declared bankruptcy, and reorganized as the Chicago, Milwaukee, St. Paul and Pacific Railroad in 1928. As the Milwaukee Road continued to face financial turmoil, branch lines began to see deteriorated conditions. In 1980, the Milwaukee Road sought to abandon significant trackage in South Dakota, including this line.  The Dell Rapids to Egan segment would be abandoned, while the Elk Point to Dell Rapids segment sold to the State of South Dakota.  The D&I Railroad was selected to operate the line.  The State of South Dakota sold the line to the D&I in 2021, and today, D&I continues to operate the line.

Located between Fairview and Hudson, this pony truss bridge crosses the Big Sioux River at Oak Ridge. The previous bridge at this location utilized a through plate girder span. In 1932, it was decided to rebuild the bridge using a pair of secondhand spans. A 123-foot standard 6-panel pin connected Pratt pony truss span, originally fabricated in 1900 for Bridge #Z-1534 near Neola, Iowa would be installed as the main span of the bridge, and a 50-foot deck plate girder span, originally fabricated in 1904 at Bridge #I-794 across the Crooked River at Elmira, Missouri would be added to the south end of the bridge. The entire bridge would be set onto timber pile substructures, and timber pile trestle approaches were installed at either end. This design of truss was the standard pony truss design of the Milwaukee Road, with numerous examples constructed throughout the system. Railroads often reused steel and iron spans to save costs on bridge replacements along branch lines. Several of the timber pile substructures would be reconstructed with steel piles in the early 2010s. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked the bridge as being regionally significant, due to the truss design and relocation history.

Citations

Builders and build dates Milwaukee Road Bridge Records at the South Dakota State Historical Society
Railroad History Citation ICC Valuation Information, Compiled by Richard S. Steele