Railroad Archives Online
- CollectionD0036 - George Werkema Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3002 - Diesel Locomotives
- 61 more...
- Itemimg162 - Great Northern Diesel Locomotive 721 at Skykomish, Washington, 1965
- Itemimg163 - Great Northern Diesel Locomotive 734 at Monroe, Washington, 1968
- Itemimg164 - Great Northern Diesel Locomotive 902 at Minneapolis, Minnesota, 1966
- Itemimg165 - Great Northern Diesel Locomotive 2006 at Minneapolis, Minnesota, 1965
- Itemimg166 - Great Northern Diesel Locomotive 2012 at Minneapolis, Minnesota, 1968
- Itemimg167 - Great Northern Diesel Locomotive 2500 at Minneapolis, Minnesota, 1968
- Itemimg168 - Great Northern Diesel Locomotive 2521 at Vancouver, British Columbia, 1967
- Itemimg169 - Great Northern Diesel Locomotive 2527 at Minneapolis, Minnesota, 1968
- Itemimg17 - Great Northern Diesel Locomotive 227 at Spokane, Washington, undated
- 158 more...