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 3007 - Tunnels
- 19 more...
- ItemJMF04-02757.0 - Northern Pacific tracks and buildings at Martin, Washington, circa 1950.
- ItemJMF04-02771.0 - Northern Pacific mainline near Martin, Washington, in 1952.
- ItemJMF04-02877.0 - Northern Pacific Stampede Tunnel, Washington State, circa 1890.
- ItemJMF04-03178.0 - Northern Pacific tunnel at Grangeville, Idaho, circa 1910.
- ItemJMF04-03191.0 - Northern Pacific tunnel at Hoppers, Montana, in 1952.
- ItemJMF04-03192.0 - Northern Pacific tunnel at Hoppers, Montana, in 1952.