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

Northern Pacific 4025, a class Z-3, works steam on an eastbound extra freight near Saltese, Montana, on May 28, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train.

Northern Pacific steam locomotive 4025 at Saltese, Montana, on May 28, 1952. Number 4025 is a class Z-3 built by Alco-Brooks in 1920. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Helper Northern Pacific locomotive number 4025 picks up a staff and respirator at Stampede, Washington, to proceed through Tunnel 4 and then Tunnel 3, the Stampede Tunnel, circa 1925. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, telegraph station, railroad crew.

Helper Northern Pacific locomotive number 4025 picks up a staff and respirator at Stampede, Washington, to proceed through Tunnel 4 and then Tunnel 3, the Stampede Tunnel, circa 1925. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, telegraph station, railroad crew.

Northern Pacific steam locomotive 4025 picks up orders at New Stampede, Washington, circa 1925. The Z-3 Mallet was built by the American Locomotive Company in Dunkirk, New York, in 1920, and scrapped in South Tacoma, Washington, in 1958. Photo by J.A. Turner. Other Subject Classes: steam locomotive, semaphore signal

Helper Northern Pacific locomotive number 4025 picks up a staff and respirator at Stampede, Washington, to proceed through Tunnel 4 and then Tunnel 3, the Stampede Tunnel, circa 1927. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, telegraph station, railroad crew.

Northern Pacific steam locomotive 403 on September 14, 1916. Number 403 is a class D-6 built by Rogers in 1899. Photo by Charles R. Iles, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 412 at Brainerd, Minnesota, on July 17, 1916. Number 412 is a class D-5 built by Baldwin in 1889. Photo by Charles R. Iles, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 423 with a passenger train at Elma, Washington, circa 1900. Number 423 is a class D-3 built by Baldwin in 1891. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo