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: Cross Sections, Garrison Tunnel, west of Garrison, Montana, Line Segment 042, Milepost 52.1. Sheet 1263 - 11, undated.

Northern Pacific Engineering Drawing: Cross Sections, Garrison Tunnel, west of Garrison, Montana, Line Segment 042, Milepost 52.1. Sheet 1263 - 11, undated.

Northern Pacific Engineering Drawing: Deck Plan, Bridge 51 - Hell Gate River, west of Garrison, Montana, Line Segment 042, Milepost 51.6. Sheet 1281 - 3, undated.

Northern Pacific Engineering Drawing: Forms for Tunnel, Garrison Tunnel, west of Garrison, Montana, Line Segment 042, Milepost 52.1. Sheet 1058 - 19, undated.

Northern Pacific Engineering Drawing: Masonry as Constructed, Bridge 51 - Hell Gate River, west of Garrison, Montana, Line Segment 042, Milepost 51.6. Sheet 1281 - 3, 1909. Note: Steel spans

Northern Pacific Engineering Drawing: Masonry as Constructed, Bridge 51 - Hell Gate River, west of Garrison, Montana, Line Segment 042, Milepost 51.6. Sheet 1281 - 3, undated.

Northern Pacific Engineering Drawing: Masonry as Constructed, Bridge 51 - Hell Gate River, west of Garrison, Montana, Line Segment 042, Milepost 51.6. Sheet 1281 - 3, undated.