Northern Pacific 2502, a U25C, leads two sisters, 2505 and 2506 on eastbound freight number 600 across the viaduct at Sandpoint Idaho, on April 15, 1965. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive, freight train.

Northern Pacific 5407, an Electro-Motive Division FT, hauls scheduled freight number 675 across the Stillaguamish River bridge north (railroad west) of Arlington, Washington, in 1955. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive, freight train, truss bridge.

Northern Pacific 557, a GP7, leads the eastbound Auburn Local freight through Quendall, Washington, in 1952. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive, freight train, trestle bridge.

Northern Pacific footbridge at Martin, Washington, in 1943. Wood bridge, former route of switchback, mainline tracks. Photo by J.M. Fredrickson . Other Subject Classes: bridge, track, right of way

Northern Pacific footbridge at Martin, Washington, in 1945. Wood bridge buckling under heavy snow. Photo by J.M. Fredrickson . Other Subject Classes: bridge

Northern Pacific mainline at Stampede Pass, Washington Territory, circa 1887. Three levels of track on switchback, timber trestles, logged hillside. J.M. Fredrickson collection. Other Subject Classes: track, switchback, bridge, mountains

Northern Pacific steam locomotive 1361 at Bellingham, Washington with train on waterfront trestle. Other subject categories: Locomotive-Steam, Train-Freight, S-4, Bridge-Trestle

Northern Pacific 1612 hauls the eastbound (south) Darrington Logger across the Stillaguamish River bridge at Arlington, Washington, on May 25, 1955. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, truss bridge.