Railroad Archives Online
- CollectionD0011 - James M. Fredrickson Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3002 - Diesel locomotives
- 644 more...
- ItemJMF11-10047.0 - Northern Pacific Railroad Diesel Locomotive number 560 at Tacoma, Washington in 1987.
- ItemJMF20-06302.0 - Northern Pacific Railway diesel locomotive 239 at Auburn, Washington on December 29, 1970.
- ItemJMF20-06302.1 - Northern Pacific Railway diesel locomotive 239 at Auburn, Washington on December 29, 1970.
- ItemJMF20-06302.2 - Northern Pacific Railway diesel locomotive 239 at Auburn, Washington on December 29, 1970.
- ItemJMF20-06300.0 - Northern Pacific Railway diesel locomotive 5410 at Stampede, Washington in 1949.