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
- 62 more...
- ItemBB019956 - Northern Pacific Engineering Drawing: General Plan, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB020028 - Northern Pacific Engineering Drawing: General Plan and Details of Tunnel Portal, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020029 - Northern Pacific Engineering Drawing: Details of Tunnel Line, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020030 - Northern Pacific Engineering Drawing: Details - Reinforcement Schedule, Tunnel Number 6, Near Quartz, Montana, undated
- ItemBB020031 - Northern Pacific Engineering Drawing: Details - Reinforcement Schedule, Tunnel Number 6, Near Quartz, Montana, undated
- 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
- 58 more...