Great Northern Engineering Drawing: Flathead Tunnel Diesel Fuel Storage for Generator at Flathead Tunnel, Montana, prepared in 1966. Burlington Northern File Number 3A-400-35, Reference Number 10111.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1966. Burlington Northern File Number E-53-33-82, Reference Number 10101.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1966. Burlington Northern File Number E-53-33-82, Reference Number 10102.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1967. Burlington Northern File Number E-53-34-5, Reference Number 10105.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1968. Burlington Northern File Number TWIN MEADOWS,MT., Reference Number 10110.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1968. Burlington Northern File Number 973D737, Reference Number 10109, Sheet 003.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1969. Burlington Northern File Number PD-15733, Reference Number 10110, Sheet 001.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1970. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 017.