Railroad Archives Online
- CollectionD0504b - Al Christianson Collection - Friends of the Burlington Northern Railroad
- Series001 - Burlington Northern Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3002 - Diesel Locomotives
- 412 more...
- ItemChristianson000492 - Burlington Northern Diesel Locomotive 6635 at Saint Paul, Minnesota in 1980
- ItemChristianson000493 - Burlington Northern Diesel Locomotive 6636 at Minneapolis, Minnesota in 1980
- ItemChristianson000494 - Burlington Northern Diesel Locomotive 6642 at Minneapolis, Minnesota in 1980
- ItemChristianson000495 - Burlington Northern Diesel Locomotive 6658 at Portland, Oregon in 1982
- ItemChristianson000496 - Burlington Northern Diesel Locomotive 6701 at Coon Rapids, Minnesota in 1981
- ItemChristianson000497 - Burlington Northern Diesel Locomotive 6709 at Prescott, Wisconsin in 1982
- ItemChristianson000498 - Burlington Northern Diesel Locomotive 6710 at Newport, Minnesota in 1982
- ItemChristianson000499 - Burlington Northern Diesel Locomotive 6724 in 1981
- ItemChristianson000500 - Burlington Northern Diesel Locomotive 6735 at Saint Paul, Minnesota in 1981
- 138 more...