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 3003 - Freight Cars
- 48 more...
- Itemimg463 - Great Northern Boxcar 48827 at Boulder, Colorado, 1965
- Itemimg464 - Great Northern Boxcar 50545 at Denver, Colorado, 1965
- Itemimg465 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg466 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg467 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg468 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg469 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg470 - Great Northern Boxcar 50561 at Denver, Colorado, 1964
- Itemimg471 - Great Northern Boxcar 51838 at Denver, Colorado, 1966
- 462 more...