Railroad Archives Online
- CollectionD0027 - Timothy Miller Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1012 - Cartographic materials
- Subseries Level 2002 - Plats
- 1135 more...
- ItemPlat012526 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1933
- ItemPlat012542 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1931
- ItemPlat012543 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1931
- ItemPlat012544 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1931
- ItemPlat012545 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1931
- ItemPlat012546 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1917
- ItemPlat012547 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1917
- ItemPlat012548 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1917
- ItemPlat012549 - Plat Map of Northern Pacific Facilities at Helena, Montana, 1917
- 691 more...