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
- 176 more...
- ItemWerkema307 - Northern Pacific hopper car number 73086 at Longmont, Colorado, in 1985.
- ItemWerkema308 - Northern Pacific hopper car number 75208 at Idaho Falls, Idaho, in 1981.
- ItemWerkema309 - Northern Pacific hopper car number 75219 at Amarillo, Texas, in 1980.
- ItemWerkema310 - Northern Pacific hopper car number 75243 at Denver, Colorado, in 1976.
- ItemWerkema311 - Northern Pacific hopper car number 75271 at Denver, Colorado, in 1965.
- ItemWerkema312 - Northern Pacific hopper car number 75352 at Bellingham, Washington, in 1992.
- ItemWerkema313 - Northern Pacific hopper car number 75375 at Bellingham, Washington, in 1992.
- ItemWerkema314 - Northern Pacific hopper car number 75476 at Bellingham, Washington, in 1977.
- ItemWerkema315 - Northern Pacific hopper car number 75479 at Pasco, Washington, in 1990.
- 38 more...