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
- 55 more...
- ItemBB017641 - Northern Pacific Engineering Drawing: Blast Protection, Bozeman Tunnel, Muir, Montana, undated
- ItemBB017642 - Northern Pacific Engineering Drawing: Shop Plan - Safety Ladder, Bozeman Tunnel, Muir, Montana, undated
- ItemBB017643 - Northern Pacific Engineering Drawing: North Wall Sketch, Bozeman Tunnel, Muir, Montana, undated
- ItemBB017644 - Northern Pacific Engineering Drawing: Reinforcement Section, Bozeman Tunnel, Muir, Montana, 1944
- ItemBB017818 - Northern Pacific Engineering Drawing: Replace Wall and Arch, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017819 - Northern Pacific Engineering Drawing: Detail of Forms, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB019955 - Northern Pacific Engineering Drawing: Tunnel and Ribs, Mullan Tunnel, Blossburg, Montana, undated
- 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
- 65 more...