Railroad Archives Online
- CollectionD0288 - Terence Wahl Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- ItemTRWahl0227 - Great Northern Caboose X700, Bellingham, Washington, undated
- ItemTRWahl0334 - Great Northern Caboose X523, Bellingham, Washington, undated
- ItemTRWahl0346 - Great Northern Caboose X211, Bellingham, Washington, undated
- ItemTRWahl0478 - Great Northern Caboose X629, Bellingham, Washington, undated
- ItemTRWahl0546 - Great Northern Caboose X578, South Bellingham, Washington, undated
- 11 more...