Railroad Archives Online
- 宗卷E0477 - BNSF Maps, Drawings and Records Collection
- 系列003 - Great Northern Railway Company (U.S.)
- 次系列009 - Engineering Records
- 008 - Tunnels
- 物件EBP0955 - Great Northern Technical Drawing, Cascade Tunnel, Washington, 1926
- 物件EBP0959 - Great Northern Technical Drawing, Cascade Tunnel, Washington, 1926
- 物件EBP0965 - Great Northern Technical Drawing, Cascade Tunnel, Washington, 1926
- 物件EBP0966 - Great Northern Technical Drawing, Cascade Tunnel, Washington, 1926
- 物件EBP4377 - Montana Central Railway Tunnel Technical Drawing, 1911