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Cascadia Park Bridge


Cascadia Park Bridge

Photo taken by Michael Goff in June 2011


BH Photo #204546


The Cascadia Park Bridge is one of only three known timber truss style bridges remaining within the state of Oregon. The other remaining timber truss structures are the Middle Fork Willamette River Bridge near Oakridge and the Mott Bridge in Douglas County. The bridge is located at the entrance to Cascadia State Park just south of OR-22 east of Sweet Home.

The Cascadia Park Bridge was originally constructed by Linn County in 1928 using design plans prepared by the Oregon State Highway Department under the guidance of state bridge engineer Conde B. McCullough. Throughout the 1950ís and 60ís the bridge had many small replacement and rehabilitation projects that rebuilt many portions of the original bridge.

In 1994 the Oregon Department of Transportation reconstructed the entire bridge. The plans for the reconstruction were prepared for ODOT by the consulting firm of CH2MHill. The new bridge features glue-laminated timbers and steel connection details, which were a contrast to the typical timber connections used in the past structures.

The latest version of the Cascadia Park Bridge consists of five spans featuring a single 120-foot timber Howe deck truss flanked by two 19-foot approach trestle spans at each end of the bridge. The total length of the structure in 196-feet and features a 22-foot wide deck carrying a 17-foot roadway and a 4.5-foot sidewalk. These dimensions are basically identical to the original structure built in 1928, the only real modification is the timber materials and connection details of the modern structure.


Timber Howe deck truss bridge over South Santiam River on Cascadia Drive
Linn County, Oregon
Open to traffic
Built 1928, Reconstructed 1951, Reconstructed 1994
- CH2M Hill of Corvallis, Oregon (1994 - Consulting Engineering Firm)
- Conde B. McCullough of Redfield, South Dakota (1928 - Bridge Engineer)
- Douglas E. Johnson (1994 - Designer)
- Glenn S. Paxson of Salem, Oregon (1951 - Bridge Engineer)
Timber Howe deck truss
Length of largest span: 120.1 ft.
Total length: 198.2 ft.
Deck width: 17.1 ft.
Also called
South Santiam River Bridge
Approximate latitude, longitude
+44.39778, -122.48111   (decimal degrees)
44°23'52" N, 122°28'52" W   (degrees°minutes'seconds")
Approximate UTM coordinates
10/541322/4916185 (zone/easting/northing)
Quadrangle map:
Average daily traffic (as of 2006)
Inventory numbers
OR 17350 (Oregon Dept. of Transportation structure number)
BH 30085 (Bridgehunter.com ID)
Inspection report (as of November 2009)
Overall condition: Fair
Superstructure condition rating: Satisfactory (6 out of 9)
Substructure condition rating: Fair (5 out of 9)
Deck condition rating: Good (7 out of 9)
Sufficiency rating: 67.7 (out of 100)
View more at BridgeReports.com

Update Log 

  • July 20, 2011: New photos from Michael Goff