4 votes

Grand Coulee Bridge


Coulee Dam Bridge

Side elevation from the northeast

Photo taken by Mike Goff in May 2012


BH Photo #231742

Street View 


The Bureau of Reclamation originally proposed to build a suspension bridge just downstream of Grand Coulee Dam but abandoned that concept in favor of a cantilever structure. Tests borings revealed that the bridge site’s geology was unsuitable for construction of cable anchorages. The cantilever design was also favored by local steel suppliers and contractors who felt they were in a better position to bid for work on this type of structure. Western Construction Company was awarded the contract to build the piers and abutments in February 1934 and commenced work immediately. The contractor experienced problems with high water and landslides and at one point fell seven months behind schedule. Several temporary footbridges and a trestle were built to facilitate construction efforts on the dam itself during this period. The Pomeroy Company began erection of the steel superstructure in the summer of 1934 and the bridge opened for traffic on January 24, 1936.


Cantilevered through truss bridge over Columbia River on WA 155 in Coulee Dam
Coulee Dam, Okanogan County, Washington, and Douglas County, Washington
Open to traffic
Built 1935
- J.H. Pomeroy of San Francisco, California (Superstructure Contractor)
- Washington Department of Highways (Engineer)
- Western Construction of Spokane, Washington (Substructure Contractor)
Cantilever steel Warren through truss with Wichert deck truss elements.
Length of largest span: 549.9 ft.
Total length: 1,089.0 ft.
Deck width: 20.3 ft.
Vertical clearance above deck: 14.5 ft.
Posted to the National Register of Historic Places on July 16, 1982
Also called
Coulee Dam Bridge
Approximate latitude, longitude
+47.96534, -118.98235   (decimal degrees)
47°57'55" N, 118°58'56" W   (degrees°minutes'seconds")
Approximate UTM coordinates
11/352029/5314350 (zone/easting/northing)
Quadrangle map:
Grand Coulee Dam
Average daily traffic (as of 2016)
Inventory numbers
NRHP 82004267 (National Register of Historic Places reference number)
BH 34413 (Bridgehunter.com ID)
Inspection report (as of October 2017)
Overall condition: Fair
Superstructure condition rating: Fair (5 out of 9)
Substructure condition rating: Good (7 out of 9)
Deck condition rating: Satisfactory (6 out of 9)
Sufficiency rating: 46.8 (out of 100)
View more at BridgeReports.com

Update Log 

  • October 12, 2021: New photo from Geoff Hubbs
  • April 22, 2018: Updated by Richard Doody: Added historical info to description
  • February 11, 2013: Updated by Nathan Holth: Added Builders
  • May 10, 2012: New photos from Mike Goff
  • March 25, 2011: New photos from Michael Goff
  • December 16, 2008: Updated by Michael Goff

Related Bridges 



Grand Coulee Bridge
Posted May 19, 2021, by Nathan Holth (webmaster [at] historicbridges [dot] org)

Its just discussions at this time, but the first mutterings of demolition and replacement have begun for this magnificent and highly significant historic bridge.


Columbia River Bridge
Posted April 26, 2010, by Todd D. Walker (mrwalk08 [at] aol [dot] com)

It seems the further west you go, the better treatment of and appreciation for truss and other notable "non UCEB" bridges is evident. Imangine driving US 101, or the Pacific Coast Highway, and every bridge "an ugly slab of dime a dozen CONCRETE!" It would be TERRIBLE! Back east that "nightmare" is coming true each time demolition companies accept tax-payer dollars.

Columbia River Bridge
Posted April 25, 2010, by Nathan Holth (form3 [at] historicbridges [dot] org)

This is a enormous, magnificent bridge which is dwarfed by the even larger Grand Coulee Dam. By the way, the Grand Coulee Dam also has a large, multi-span open-spandrel concrete deck arch bridge on top.