Northern Pacific steam locomotive 5101 at Livingston, Montana, on August 18, 1949. Number 5101 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 5101 at Livingston, Montana, on May 29, 1954. Number 5101 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 5102 at the coal dock in Livingston, Montana, on May 28, 1954. Number 5102 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 5102 at the coal dock in Livingston, Montana, on May 28, 1954. Number 5102 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 5102 at the coal dock in Livingston, Montana, on May 28, 1954. Number 5102 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 5105 at Livingston, Montana, on August 23, 1943. Number 5105 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 5106, a class Z-6, leads an eastbound extra freight at Livingston, Montana, on May 23, 1952. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight train.

Northern Pacific steam locomotive 5106 at Livingston, Montana, on June 07, 1955. Number 5106 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 5106 at Livingston, Montana, on June 07, 1955. Number 5106 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 5106, a class Z-6, and 2663, a class A-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.