Northern Pacific 5120 and 5100, both class Z-6 steam locomotives, wait at Garrison, Montana for their next assignment to help trains over Mullan Pass on May 24, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, helper locomotive, telegraph station.

Northern Pacific steam locomotive 5100 at Garrison, Montana, on May 24, 1952. Number 5100 is a class Z-6 built by Alco-Schenectady in 1936. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5100 at Garrison in Montana, circa 1955. Number 5100 is a class Z-6 built by Alco-Schenectady in 1936. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4025 at Garrison, 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

Northern Pacific steam locomotive 4021 at Garrison, Montana, on September 08, 1946. Number 4021 is a class Z-3 built by Alco-Brooks in 1920. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 4017 at Garrison, Montana, on September 08, 1946. Number 4017 is a class Z-3 built by Alco-Brooks in 1917. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 2232 at Garrison, Montana, on September 02, 1953. Number 2232 is a class Q-5 built by Alco-Brooks in 1920. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 2232 at Garrison, Montana, in September 1953. Number 2232 is a class Q-5 built by Alco-Brooks in 1920. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 2131 at Garrison, Montana, on May 22, 1951. Number 2131 is a class Q-1 built by Alco-Schenectady in 1904. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 2131 at Garrison, Montana, on May 22, 1951. Number 2131 is a class Q-1 built by Alco-Schenectady in 1904. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo