Railroad Archives Online
- CollectionD0027 - Timothy Miller Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1009 - Engineering Records
- Subseries Level 2008 - Physical plant drawing
- Subseries Level 3008 - Tunnels
- 242 more...
- ItemStruc004471 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1967
- ItemStruc004472 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1966
- ItemStruc004473 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1966
- ItemStruc004474 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1973
- ItemStruc004475 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1973
- ItemStruc004476 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1974
- ItemStruc004477 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, undated
- ItemStruc004478 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1971
- ItemStruc004479 - Great Northern Engineering Drawing, Flathead Tunnel, Montana, 1973
- 101 more...