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 3005 - Maintenance of Way cars
- ItemWerkema266 - Northern Pacific gondola car number 85132, at Belen, New Mexico, in 1989.
- ItemWerkema269 - Northern Pacific gondola car number 85421, at Denver, Colorado, in 1972.
- ItemWerkema267 - Northern Pacific gondola car number 85324, at Pasco, Washington, in 1971.
- ItemWerkema268 - Northern Pacific gondola car number 85356, at Skykomish, Washington, in 1988.
- ItemWerkema270 - Northern Pacific gondola car number 87077, at Amarillo, Texas, in 1976.
- ItemWerkema271 - The unloading gate detail of Northern Pacific Hart ballast car 87384 at Denver, Colorado, in 1973.
- ItemWerkema272 - Northern Pacific Hart ballast car 87384 at Denver, Colorado, in 1973.
- ItemWerkema273 - Northern Pacific open hopper car number 87467, at Skykomish, Washington, in 1988.
- ItemWerkema274 - Northern Pacific open hopper car number 87536, at Bellingham, Washington, in 1982.
- 20 more...