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 3006 - Cabooses (Railroads)
- ItemWerkema358 - Northern Pacific steel caboose 10141 at Denver, Colorado, in 1970.
- ItemWerkema359 - Burlington Northern steel caboose 10050 at Longmont, Colorado, in 1989.
- ItemWerkema360 - Burlington Northern steel caboose 10050 at Longmont, Colorado, in 1989.
- ItemWerkema361 - Northern Pacific wood caboose 1238 at Seattle, Washington, in 1977.
- ItemWerkema362 - Northern Pacific wood caboose 1238 at Seattle, Washington, in 1977.
- ItemWerkema363 - Northern Pacific wood caboose 1314 at Sumas, Washington, in 1968.
- ItemWerkema364 - Northern Pacific wood caboose 1314 at Sumas, Washington, in 1968.
- ItemWerkema365 - Northern Pacific wood caboose 1314 at Sumas, Washington, in 1968.
- 5 more...