Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 002.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 005.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10105, Sheet 007.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D736, Reference Number 10101, Sheet 001.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10101, Sheet 001.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10102, Sheet 003.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 003.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D754, Reference Number 10102, Sheet 010.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10101, Sheet 004.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number 973D737, Reference Number 10101, Sheet 006.