Great Northern Blueprint Number 1333-9-4, Great Northern New Cascade Tunnel Section Looking East, 1926. Other subject categories: Drawing

Great Northern Blueprint Number 1333-9-7, Great Northern Proposed Section of the New Cascade Tunnel, 1926. Other subject categories: Drawing

Great Northern Blueprint Number 1333-9-6, Great Northern New Cascade Tunnel Cross Sections, 1926. Other subject categories: Drawing

Great Northern Blueprint Number 1333-9-5, Great Northern Details of Trolley Suports in the New Cascade Tunnel, 1926. Other subject categories: Drawing

Great Northern Blueprint Number 1249-28, Montana Central Railway Montana Central, Tunnel Sections, 1911. Other subject categories: Drawing

Northern Pacific Engineering Drawing: 8 Inch Beam Rib Section, Garrison Tunnel, west of Garrison, Montana, Line Segment 042, Milepost 52.1. Sheet VF 1263 - 11, undated.

Northern Pacific Engineering Drawing: 8 Inch Beam Rib Section, Garrison Tunnel, west of Garrison, Montana, Line Segment 042, Milepost 52.1. Sheet VF 1263 - 11, undated.

Northern Pacific Engineering Drawing: Blast Protection, Bozeman Tunnel, Muir, Montana, Line Segment 041, Milepost 127.5. Sheet 1268 - 14, undated.

Northern Pacific Engineering Drawing: Boiler House, Mullan Tunnel, Blossburg, Montana, Line Segment 042, Milepost 19.6, undated.

Northern Pacific Engineering Drawing: Boiler House, Mullan Tunnel, Blossburg, Montana, Line Segment 042, Milepost 19.6, undated.