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
- 11 more...
- ItemStruc001250 - Great Northern Engineering Drawing, Flathead Tunnel at Twin Meadows, Montana, 1975
- ItemStruc001251 - Great Northern Engineering Drawing, Flathead Tunnel at Twin Meadows, Montana, 1973
- ItemStruc001252 - Great Northern Engineering Drawing, Flathead Tunnel at Twin Meadows, Montana, 1977
- ItemStruc001433 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- ItemStruc001434 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- ItemStruc001435 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- ItemStruc001436 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- ItemStruc001437 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- ItemStruc001438 - Great Northern Engineering Drawing, Cascade Tunnel, Washington, 1956
- 332 more...