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 3002 - Depots and Freighthouses
- 1146 more...
- ItemStruc006965 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1956
- ItemStruc006966 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1956
- ItemStruc006972 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1957
- ItemStruc006981 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1960
- ItemStruc006982 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1960
- ItemStruc006983 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, undated
- ItemStruc006984 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1960
- ItemStruc006985 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1970
- ItemStruc006987 - Northern Pacific Engineering Drawing, Depot at Helena, Montana, 1902
- 507 more...