Railroad Archives Online
- CollectionD0153 - Doug Wingfield Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3002 - Diesel Locomotives
- 13 more...
- ItemWingfield.181 - Northern Pacific Diesel Locomotive 315 at Spokane, Washington, 1968
- ItemWingfield.182 - Northern Pacific Diesel Locomotive 373, 904 at Crookston, Minnesota, 1969
- ItemWingfield.183 - Northern Pacific Diesel Locomotive 373, 904 at Crookston, Minnesota, 1969
- ItemWingfield.187 - Northern Pacific Diesel Locomotive 384, 686, 679, 7114 at Sandpoint, Idaho, 1968
- ItemWingfield.188 - Northern Pacific Diesel Locomotive 101 at Interbay, Washington, 1962
- ItemWingfield.190 - Northern Pacific Diesel Locomotive 3600, 2808, 2527 at Marshall, Washington, 1968
- ItemWingfield.192 - Northern Pacific Diesel Locomotive 3600, 2808, 2527 at Marshall, Washington, 1968
- ItemWingfield.194 - Northern Pacific Diesel Locomotive 3614 at Spokane, Washington, 1968
- ItemWingfield.197 - Northern Pacific Diesel Locomotive 2512, 2510, 3617 at Marshall, Idaho, 1968
- 16 more...