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 3005 - Maintenance of Way cars
- Subseries Level 3007 - Tractor Trailers
- Subseries Level 3008 - Buses
- Subseries Level 3010 - Miscellaneous
- 1 more...