Railroad Archives Online
- FondsD0027 - Timothy Miller Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série009 - Engineering Records
- 008 - Physical plant drawing
- 008 - Tunnels
- 115 en plus...
- PièceStruc001534 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- PièceStruc001535 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1965
- PièceStruc001536 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- PièceStruc001537 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1965
- PièceStruc001538 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- PièceStruc001539 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- PièceStruc001540 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- PièceStruc001541 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- PièceStruc001542 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1964
- 228 en plus...