Railroad Archives Online
- FondsD0027 - Timothy Miller Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série009 - Engineering Records
- 008 - Physical plant drawing
- 008 - Tunnels
- 288 en plus...
- PièceStruc004517 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004518 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004519 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004520 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004521 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004522 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004523 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004524 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- PièceStruc004525 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- 55 en plus...