Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 012.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 015.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 001.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 002.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 004.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 005.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 006.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10101, Sheet 008.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10101, Sheet 005.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10101, Sheet 005.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-1592-1, Reference Number 10102.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10102, Sheet 004.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-7617, Reference Number 10102.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-21054, Reference Number 10105.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 008.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 009.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number EM7333-4000, Reference Number 10111.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number TWIN MEADOWS,MT., Reference Number 10109.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number 9883-1, Reference Number 10108.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number TWIN MEADOWS,MT., Reference Number 10112.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number 369D419, Reference Number 10107.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1973. Burlington Northern File Number 369D419, Reference Number 10107.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1974. Burlington Northern File Number TWIN MEADOWS,MT., Reference Number 10108.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1974. Burlington Northern File Number EM7337-4000, Reference Number 10101.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1975. Burlington Northern File Number PD-15727, Reference Number 10109.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, undated. Burlington Northern File Number TWIN MEADOWS,MT., Reference Number 101.