Railroad Archives Online
- FondsD0027 - Timothy Miller Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série009 - Engineering Records
- 008 - Physical plant drawing
- 008 - Tunnels
- 254 en plus...
- PièceStruc004483 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004484 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004485 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004486 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004487 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004488 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004489 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004490 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004491 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- 89 en plus...