Northern Pacific switchback at Stampede Pass, Washington Territory, circa 1887. Mainline, two levels of switchback, snowshed. Museum photo. J.M. Fredrickson collection. Other Subject Classes: track, switchback, snowshed, mountain

Northern Pacific Class Z-3 steam locomotive number 4024 leads a westbound freight train toward Stampede Tunnel at Martin, Washington, circa 1925. Photo by J.A. Turner. Other Subject Classes: steam locomotive, freight train

Northern Pacific Class Z-3 steam locomotive number 4011 leads a westbound freight train near Martin, Washington, circa 1925. Photo by J.A. Turner. Other Subject Classes: steam locomotive, freight train

Northern Pacific Class Z-3 steam locomotive number 4006 leads a westbound freight train near Martin, Washington, in 1924. Photo by J.A. Turner. Other Subject Classes: steam locomotive, freight train

Northern Pacific Class Z-3 steam locomotive number 4005 is the rear helper on a westbound freight train near Martin, Washington, in 1924. Photo by J.A. Turner. Other Subject Classes: steam locomotive, freight train

The rear helper engine on an extra freight west between Easton and Martin, Washington, circa 1917. Photo by Ralph Parsons, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight train, snow and ice.

A train crew member walks the top of a train between Easton and Martin, Washington, circa 1917. Note helper locomotive pushing behind the caboose. Photo by Ralph Parsons, J.M. Fredrickson collection. Other Subject Classes: freight train, steam locomotive, railroad crew.

An extra freight west rounds the curve near Tunnel 3 east of Martin, Washington, circa 1917. Photo by Ralph Parsons, J.M. Fredrickson collection. Other Subject Classes: freight train, snow and ice.

A train crew member walks the top of a train between Easton and Martin, Washington, circa 1917. Note helper locomotive pushing behind the caboose. Photo by Ralph Parsons, J.M. Fredrickson collection. Other Subject Classes: freight train, steam locomotive, railroad crew.

A class Z-3 locomotive enters the cut at Tunnel 2, east of Martin, Washington, circa 1917. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight train.