Railroad Archives Online
- FondoD0011 - James M. Fredrickson Collection
- Serie004 - Northern Pacific Railroad Company
- Sottoserie014 - Photographs
- 003 - Railroad Buildings and Structures
- 001 - Bridges
- Unità documentariaJMF02-03714.1 - Bridge No. 60 on the Northern Pacific Stampede line at Lester, Washington, circa 1940.
- Unità documentariaJMF04-02506.1 - Aerial photo of Tacoma, Washington, circa 1957.
- Unità documentariaJMF04-02570.1 - Northern Pacific truss bridge at Kent, Washington, in September 28, 1924.
- Unità documentariaJMF04-02589.1 - Northern Pacific truss bridge at Eagle Gorge, Washington, in June 20, 1925.
- Unità documentariaJMF04-02603.0 - Northern Pacific bridge at Kelly Butte, Washington, in 1969.
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