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.

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

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

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

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

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