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 3005 - Maintenance of Way cars
- Itemimg226 - Great Northern Maintenance of Way Spreader X171 at Whitefish, Montana, 1990
- Itemimg227 - Great Northern Maintenance of Way Tank Car X1207 at Wenatchee, Washington, 1988
- Itemimg228 - Great Northern Diesel Locomotive Fuel Tank Car X1369 at Great Falls, Montana, 1990
- Itemimg229 - Great Northern Diesel Locomotive Fuel Tank Car X1377 at Denver, Colorado, 1985
- Itemimg230 - Great Northern Diesel Locomotive Fuel Tank Car X1377 at Denver, Colorado, 1985
- Itemimg231 - Great Northern Diesel Locomotive Fuel Tank Car X1381 at Pasco, Washington, 1992
- Itemimg232 - Great Northern Diesel Locomotive Fuel Tank Car X1395 at Portland, Oregon, 1988
- Itemimg233 - Great Northern Snow Plow X1510 at Interbay, Washington, 1973
- 44 more...