Northern Pacific 4025, a class Z-3, leads an eastbound extra freight on the Milwaukee mainline between Haugan and Saint Regis, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, river.

Northern Pacific 4025, a class Z-3, leads an eastbound extra freight on the Milwaukee mainline between Haugan and Saint Regis, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, river.

Northern Pacific 4025, a class Z-3, leads an eastbound extra freight downhill from the summit of Lookout Pass west of Haugan, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, river.

Northern Pacific 4025, a class Z-3, leads an eastbound extra freight downhill from the summit of Lookout Pass west of Haugan, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, river.