Railroad Archives Online
- FondsD0027 - Timothy Miller Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série009 - Engineering Records
- 008 - Physical plant drawing
- 008 - Tunnels
- 31 en plus...
- PièceStruc001450 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001451 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001452 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001453 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001454 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001455 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001456 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001457 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001458 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- 312 en plus...