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POVA - Box Canyon Bridge


Historical Postcard Showing Bridge Construction

View this photo at pendoreilleco.org

BH Photo #324500


Development of the Pend Oreille valley began in earnest when Lewis Larsen persuaded F.A. Blackwell, a lumberman who started in Pennsylvania and followed the supply of timber west, to build the Idaho & Washington Northern Railroad from Newport to his cement plant at Metaline Falls in 1909.

Constructing Box Canyon Bridge was the most difficult task required to complete the 80 mile shortline. The bridge was erected entirely from the south side of the canyon to avoid the expense of building a cableway plant to transfer materials to the barely accessible abutment on the north side of the canyon. The river’s depth and the swiftness of the current precluded the use of falsework and the steel trusses were placed by use of the cantilever method. The 145 foot anchor arm or shore span weighing 300 tons was erected first. It was specially designed to carry the compressive load of the 700 ton channel span it would have to support until completion as well as the 600 tons of steel rail stacked on it as a counterweight. The rails of the Idaho & Washington Northern stood 140 feet above the river when the bridge was completed in 1910. Box Canyon Dam, completed in 1961, brought the water to within a few feet of the bridge but the span and its setting are still a most impressive sight. The bridge was fabricated the Pennsylvania Steel Company and erected by McCreary & Willard of Spokane.

The railroad’s completion spurred dramatic growth in the valley’s economy and population. It was a key factor influencing the creation of Washington State’s newest county, Pend Oreille, by the 1911 legislature.

The Idaho & Washington Northern was acquired by the Milwaukee Road in 1916. The line was sold to the Pend Oreille Valley Railroad in 1980 and is still in operation.


Pratt deck truss bridge over Box Canyon Resevoir (Pend Oreille River) on Pend Oreille Valley Railroad
Pend Oreille County, Washington
Open to traffic
Built 1909
- McCreary & Willard of Spokane, Washington (Contractor)
- Pennsylvania Steel Co. of Steelton, Pennsylvania (Fabricator)
- Chicago, Milwaukee, St. Paul & Pacific Railroad (MILW)
- Idaho & Washington Northern Railroad (I&WN)
- Pend Oreille Valley Railroad (POVA)
Pratt deck truss
Posted to the National Register of Historic Places in 1982
Also called
I&WN - Box Canyon Bridge
POVA - Box Canyon Bridge
POVA - Box Canyon Bridge
POVA - Pend Oreille River Bridge
MILW - Box Canyon Bridge
I&WN - Pend Oreille River Bridge
MILW - Pend Oreille River Bridge
Approximate latitude, longitude
+48.78053, -117.41020   (decimal degrees)
48°46'50" N, 117°24'37" W   (degrees°minutes'seconds")
Approximate UTM coordinates
11/469865/5403140 (zone/easting/northing)
Quadrangle map:
Inventory numbers
NRHP 82004270 (National Register of Historic Places reference number)
BH 67563 (Bridgehunter.com ID)

Update Log 

  • July 10, 2019: New photos from Mike Garland
  • July 5, 2019: New photos from Mike Garland
  • April 20, 2018: Updated by Richard Doody: Added historical data to description
  • February 7, 2017: New photos from Kyle Jarvis
  • May 13, 2015: Added by Nathan Holth