Railroad Archives Online
- FondsD0027 - Timothy Miller Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série009 - Engineering Records
- 008 - Physical plant drawing
- 008 - Tunnels
- 171 en plus...
- PièceStruc001590 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001591 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001592 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001593 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001594 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001595 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001596 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001597 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- PièceStruc001598 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1957
- 172 en plus...