Railroad Archives Online
- CollectionD0011 - James M. Fredrickson Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2003 - Railroad Buildings and Structures
- Subseries Level 3005 - Signals and Signs
- 65 more...
- ItemJMF04-02468.0 - Northern Pacific signal equipment at Tacoma, Washington, in 1967.
- ItemJMF04-02469.0 - Northern Pacific signal equipment at Tacoma, Washington, in 1967.
- ItemJMF04-02758.0 - Northern Pacific signal bridge at Martin, Washington, circa 1960.
- ItemJMF04-02879.0 - Road sign at Stampede Pass, Washington, in 1944.
- ItemJMF04-03011.0 - Northern Pacific control panel at Tacoma, Washington, circa 1962.
- ItemJMF04-03012.0 - Northern Pacific control panel at Tacoma, Washington, circa 1962.