Railroad Archives Online
- CollectionD0063 - Walter W. Ainsworth Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3004 - Railroad Passenger Cars
- ItemWWANT028 - A Northern Pacific passenger train at Seattle, Washington, circa 1935.
- ItemWWANT046 - Northern Pacific passenger train at Seattle, Washington, circa 1935.
- ItemWWANT081 - Northern Pacific steam locomotive leads a passenger train at Black River, Washington, circa 1941.