Northern Pacific tunnel at Borup, Washington, in 1914. Old tunnel number 6, new bypass under construction, construction workers. Photo by Corey, J.M. Fredrickson collection.. Other Subject Classes: tunnel, construction workers, track

Northern Pacific bridge and tunnel at Grangeville, Idaho, circa 1910. Colorized postcard view of timber truss bridge, timber tunnel mouth, steam locomotive emerging. J.M. Fredrickson collection. Other Subject Classes: tunnel, bridge, steam locomotive

Northern Pacific tunnel at Hoppers, Montana, May 23, 1952. Two-track tunnel in process of being daylighted, mainline being single-tracked. Photo by J.M. Fredrickson. Other Subject Classes: tunnel, track

Northern Pacific tunnel at Hoppers, Montana, May 23, 1952. Looking toward two-track tunnel in process of being daylighted, mainline being single-tracked. Photo by J.M. Fredrickson. Other Subject Classes: tunnel, track

Northern Pacific Stampede Tunnel at Martin, Washington, circa 1944. East portal and snowshed of tunnel, station, signal, outbuildings, in heavy snow. Photo by J.M. Fredrickson . Other Subject Classes: tunnel, station, signal

Northern Pacific tracks at Martin, Washington, in February 1945. Track and buildings, east portal of Stampede Tunnel, in snow. Photo by J.M. Fredrickson . Other Subject Classes: track, town scene, tunnel

South portal of Great Northern Railway tunnel at Seattle, Washington. South Portal and interlocking. Other subject classes: Tunnel Portal

Southern Pacific Railroad tunnels at Donner Summit, California on August 27, 1975. Waiting for a westbound extra freight train at Donner Summit in 1975. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive, tunnel.

Staff machine for operating trains through single-track territory, as used by Northern Pacific between Stampede and Martin, Washington. Copy from Union Pacific rule book. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment