Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1890. Burlington Northern File Number 272-30, Reference Number 10108.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1891. Burlington Northern File Number 272-30, Reference Number 10102.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1910. Burlington Northern File Number 272-30, Reference Number 10111.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1911. Burlington Northern File Number 272-30, Reference Number 10109.

Northern Pacific Engineering Drawing: Subway Under 7th Street - General Plan at Olympia, Washington, prepared in 1911. Burlington Northern File Number 272-30, Reference Number 10109.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1911. Burlington Northern File Number 272-30, Reference Number 10109.

Northern Pacific Engineering Drawing: Subway Under 7th Street - General Plan at Olympia, Washington, prepared in 1911. Burlington Northern File Number 272-30, Reference Number 10109, Sheet 001.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1913. Burlington Northern File Number 272-30, Reference Number 10104.

Northern Pacific Engineering Drawing: Subway Under 7th Street - General Details at Olympia, Washington, prepared in 1913. Burlington Northern File Number 272-30, Reference Number 10105, Sheet 002.

Northern Pacific Engineering Drawing: Subway Under 7th Street at Olympia, Washington, prepared in 1913. Burlington Northern File Number 272-30, Reference Number 10110.