Railroad Archives Online
- CollectionD0036 - George Werkema Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3003 - Freight Cars
- 162 more...
- ItemWerkema293 - Northern Pacific hopper car number 70374 at Denver, Colorado, in 1973.
- ItemWerkema294 - Northern Pacific hopper car number 71022 at Albuquerque, New Mexico, in 1978.
- ItemWerkema295 - Northern Pacific hopper car number 71022 at Albuquerque, New Mexico, in 1980.
- ItemWerkema296 - Northern Pacific hopper car number 71104 at Albuquerque, New Mexico, in 1973.
- ItemWerkema297 - Northern Pacific hopper car number 71104 at Albuquerque, New Mexico, in 1978.
- ItemWerkema298 - Northern Pacific hopper car number 72064 at Albuquerque, New Mexico, in 1980.
- ItemWerkema299 - Northern Pacific hopper car number 72065 at Albuquerque, New Mexico, in 1978.
- ItemWerkema300 - Northern Pacific hopper car number 72065 at Albuquerque, New Mexico, in 1981.
- ItemWerkema301 - Northern Pacific hopper car number 72065 at Albuquerque, New Mexico, in 1981.
- 52 more...