Railroad Archives Online
- CollectionD0036 - George Werkema Collection
- Series010 - Other Railroads
- Subseries Level 1014 - Photographs
- Subseries Level 2003 - Railroads--Buildings and Structures
- Subseries Level 3001 - Railroad Bridges
- ItemWerkema571 - Soo Line Railroad Sheyenne River viaduct at Valley City, North Dakota, in 2003.