Railroad Archives Online
- CollectionD0027 - Timothy Miller Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1009 - Engineering Records
- Subseries Level 2008 - Physical plant drawing
- Subseries Level 3008 - Tunnels
- 67 more...
- ItemBB020032 - Northern Pacific Engineering Drawing: Details Retaining Wall, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020033 - Northern Pacific Engineering Drawing: Miscellaneous Details, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020034 - Northern Pacific Engineering Drawing: Retaining Wall West End, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020035 - Northern Pacific Engineering Drawing: Retaining Wall West End, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020036 - Northern Pacific Engineering Drawing: Extension General Plan, Tunnel Number 6, Near Quartz, Montana, 1951
- ItemBB020037 - Northern Pacific Engineering Drawing: Extension Tunnel Line, Tunnel Number 6, Near Quartz, Montana, 1951
- ItemBB020742 - Northern Pacific Engineering Drawing: Proposed Tunnel Liner, Tunnel Liner near Reservation, Tacoma, Washington, undated
- ItemBB025469 - Northern Pacific Engineering Drawing: Retaining Wall, Tunnel 10 West of Quinns, West of Quinns, Montana, undated
- ItemBB025470 - Northern Pacific Engineering Drawing: Ventilating Plant, Mullan Tunnel, Blossburg, Montana, undated
- 53 more...