Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1948. Burlington Northern File Number 9531, Reference Number 10102.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1950. Burlington Northern File Number 9531, Reference Number 10104.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1951. Burlington Northern File Number 9531, Reference Number 10102.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1954. Burlington Northern File Number 9531, Reference Number 10106.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1954. Burlington Northern File Number 9531, Reference Number 10105.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1954. Burlington Northern File Number 9531, Reference Number 10106.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1954. Burlington Northern File Number 9531, Reference Number 10104.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1955. Burlington Northern File Number 9531, Reference Number 10107, Sheet 001.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1955. Burlington Northern File Number 9531, Reference Number 10110.

Great Northern Engineering Drawing: Cascade Tunnel, Washington, prepared in 1955. Burlington Northern File Number 9531, Reference Number 10112.