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 3002 - Diesel Locomotives
- ItemTRWahl0001 - Great Northern Diesel Locomotive 609, Rockport, Washington, undated
- ItemTRWahl0002 - Great Northern Diesel Locomotive with Freight Train, Kelso, Washington, August 1951
- ItemTRWahl0003 - Great Northern Diesel Locomotive 275A, Havre, Montana, undated
- ItemTRWahl0026 - Great Northern Diesel Locomotive 351C, Bellingham, Washington, undated
- ItemTRWahl0027 - Great Northern Diesel Locomotive 261A, Bellingham, Washington, undated
- ItemTRWahl0031 - Great Northern Diesel Locomotive 260A, Bellingham, Washington, undated
- 208 more...