Northern Pacific 4025, a class Z-3, on the Milwaukee mainline bridge over the Clark Fork River at Saint Regis, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, truss bridge.

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.

Northern Pacific Pile Driver 12 works on a trestle along the shore of Lake Whatcom near Bellingham, Washington, circa 1910. Note the four wheel caboose on the train. J.M. Fredrickson collection. Other Subject Classes: Pile Driver, steam locomotive, work outfit car.

A Class W3 2-8-2 locomotive hauls Northern Pacific train number 937 past Headworks Spur in the Tacoma Water System on the Green River, Washington, in 1953. Photo by J.M. Fredrickson. Other Subject Classes: freight train, steam locomotive, river.

Northern Pacific 89 pulls a mixed freight across bridge 4.2 near the coal mine at Blue Canyon, Washington, near Lake Whatcom, circa 1910. Photo by Louis Butt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight train, trestle bridge.

Northern Pacific steam locomotive 979 at Brainerd, Minnesota, on June 07, 1916. Number 979 is a class L built by Baldwin in 1883. Photo by Charles R. Iles, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo