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 in the deadlind at Livingston 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 5100 at Livingston, Montana, on August 23, 1943. 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 5100, the first class Z-6, and Northern Pacific 5001, a class Z-5, wait at the shops in Livingston, Montana, for their next assignments on June 07, 1955. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, stored locomotive.

Northern Pacific 5100, the first class Z-6, Northern Pacific 5001, a class Z-5, Northern Pacific 1795 and 1770, both class W-3, wait at the shops in Livingston, Montana, for their next assignments, on June 07, 1955. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, stored locomotive.

Northern Pacific (NP) 5100, the first class Z-6 locomotive delivered to the NP in 1936, passes the depot at Missoula, Montana, with an eastbound extra freight in 1953. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train, passenger depot.

Northern Pacific steam locomotive 5100 at Schenectady, New York in 1936. Number 5100 is a class Z-6 built by Alco-Schenectady in 1936. Photo by AH Fiedler, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5100 at South Tacoma, Washington, on May 16, 1957. Number 5100 is a class Z-6 built by Alco-Schenectady in 1936. Photo by Emery Roberts, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5100 at Tacoma, Washington, on May 16, 1957. Number 5100, a class Z-6 built by Alco-Schenectady in 1936, is parked in the deadline at Tacoma. Photo by Emery Roberts, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, deadline

Northern Pacific steam locomotive 5100 with a freight train, circa 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