Railroad Archives Online
- CollectionD0036 - George Werkema Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1014 - Photographs
- Subseries Level 2003 - Railroads--Buildings and Structures
- Subseries Level 3001 - Bridges
- 13 more...
- Itemimg1180 - Great Northern Bridge at Rock Island, Washington, 1988
- Itemimg1181 - Great Northern Bridge at Rock Island, Washington, 1988
- Itemimg1182 - Great Northern Bridge at Rock Island, Washington, 1988
- Itemimg1183 - Great Northern Bridge at Ballard, Washington, 1991
- Itemimg1184 - Great Northern Bridge at Ballard, Washington, 1991
- Itemimg1185 - Great Northern Bridge at Ballard, Washington, 1991
- Itemimg1186 - Great Northern Bridge at Ballard, Washington, 1991
- Itemimg1187 - Great Northern Bridge at Mt.Vernon, Washington, 1982
- Itemimg1188 - Great Northern Bridge at Index, Washington, 1987
- 7 more...