Great Northern Engineering Drawing: Signal Maintainer and Track Forces Building, Metal 20 Foot X 56 Foot at Harlem, Montana (also at Brookston, Minnesota), prepared in 1964. Burlington Northern File Number 9665-M1, Reference Number 10110.

Great Northern Engineering Drawing: Signal Maintainer and Track Forces Building, Metal 20 Foot X 56 Foot Standard Material Building at Harlem, Montana (also Brookston, Minnesota), prepared in 1964. Burlington Northern File Number 9665-1, Reference Number 10108.

Great Northern Engineering Drawing: Signal Maintainer and Track Forces Building, Metal 20 Foot X 56 Foot Electrical Material Building at Harlem, Montana (also Brookston, Minnesota), prepared in 1967. Burlington Northern File Number 9665-E1, Reference Number 10109.

The Mesabi Division file contains clearance diagrams for 10 railway line segments divided at Minneapolis Junction, Minnesota; Coon Creek, Minnesota; Boylston, Minnesota; Duluth, Minnesota; Cass Lake, Minnesota; Brookston, Minnesota; Kelly Lake, Minnesota; Gunn, Minnesota; Virginia, Minnesota; Saint Cloud, Minnesota, Brook Park, Minnesota; Sauk Centre, Minnesota; Cass Lake, Minnesota; Allouez, Wisconsin and Saunders, Wisconsin. Individual segment diagrams appear to have been updated in the period between 1957 and 1969.