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
- 24 more...
- ItemBB017509 - Northern Pacific Engineering Drawing: Proposed Concrete Work North, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017510 - Northern Pacific Engineering Drawing: Proposed Concrete Work South, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017511 - Northern Pacific Engineering Drawing: Proposed Blower and Ventilating, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017512 - Northern Pacific Engineering Drawing: Proposed Ventilating Nozzle Change, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017513 - Northern Pacific Engineering Drawing: Ventilating Nozzle Change and Details, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017514 - Northern Pacific Engineering Drawing: Mooring Details Fan, Mullan Tunnel, Blossburg, Montana, undated
- ItemBB017616 - Northern Pacific Engineering Drawing: General Layout, Bozeman Tunnel, Muir, Montana, undated
- ItemBB017617 - Northern Pacific Engineering Drawing: Door Details, Bozeman Tunnel, Muir, Montana, undated
- ItemBB017618 - Northern Pacific Engineering Drawing: Door Details, Bozeman Tunnel, Muir, Montana, undated
- 96 more...