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 3005 - Maintenance of Way cars
- 23 more...
- ItemJMF08-05468.1 - Northern Pacific Railroad Rotary Snow Plow Number 10 at Upham, Washington in January, 1943.
- ItemJMF08-05469.0 - Northern Pacific Railroad Rotary Snow Plow Number 10 at Martin, Washington in February 1945.
- ItemJMF08-05470.0 - Northern Pacific Railroad Rotary Snowplow Number 10 at Martin, Washington in February, 1945.
- ItemJMF08-05471.0 - Northern Pacific Railroad Rotary Snow Plow Number 10 at Martin, Washington in February 1945.
- ItemJMF08-05472.0 - Northern Pacific Railroad Rotary Snow Plow Number 42 at Martin, Washington in February, 1945.
- ItemJMF08-05473.0 - Northern Pacific Railroad Rotary Snow Plow Number 42 at Martin, Washington in February, 1945.
- ItemJMF08-05474.0 - Northern Pacific Railroad Rotary Snow Plow Number 42 at Martin, Washington in February, 1945.
- ItemJMF08-05475.0 - Northern Pacific Railroad Rotary Snow Plow Number 10 at Martin, Washington in February, 1945.
- ItemJMF08-05476.0 - Northern Pacific Railroad Rotary Snow Plow Number 42 at Martin, Washington in 1949-50.
- 40 more...