Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10102, Sheet 003.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10102, Sheet 008.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10102, Sheet 012.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15733, Reference Number 10102, Sheet 013.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 001.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 002.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 004.

Great Northern Engineering Drawing: Flathead Tunnel, Montana, prepared in 1971. Burlington Northern File Number PD-15727, Reference Number 10102, Sheet 006.

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-18050, Reference Number 10102, Sheet 004.