Railroad Archives Online
- CollectionD0288 - Terence Wahl Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2003 - Railroads--Buildings and Structures
- Subseries Level 3001 - Bridges
- ItemTRWahl0213 - Northern Pacific Bridge 61.1, Arlington, Washington, undated
- ItemTRWahl0245 - Northern Pacific Bridge 61.1, Arlington, Washington, undated
- ItemTRWahl0247 - Northern Pacific Bridge 61.1, Arlington, Washington, undated
- ItemTRWahl0248 - Northern Pacific Bridge 61.1, Arlington, Washington, undated
- ItemTRWahl0249 - Northern Pacific Bridge 61.1, Arlington, Washington, undated
- ItemTRWahl0374 - Northern Pacific Bridge 104, Acme, Washington, undated
- ItemTRWahl0375 - Northern Pacific Bridge 104, Acme, Washington, undated
- ItemTRWahl0390 - Northern Pacific Bridge 110, Deming, Washington, undated
- 5 more...