Northern Pacific steam locomotive 5011 in helper service at Livingston, Montana, circa 1952. Number 5011 is a class Z-5 built by Baldwin in 1930. Photo by Ron V. Nixon, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5011 at Livingston, Montana, in September 1953. Number 5011 is a class Z-5 built by Baldwin in 1930. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5011 at Livingston, Montana, in September 1953. Number 5011 is a class Z-5 built by Baldwin in 1930. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5011 at Livingston, Montana, in September 1953. Number 5011 is a class Z-5 built by Baldwin in 1930. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5011 at Livingston, Montana, on May 28, 1954. Number 5011 is a class Z-5 built by Baldwin in 1930. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5011 at Livingston, Montana, on May 28, 1954. Number 5011 is a class Z-5 built by Baldwin in 1930. 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, 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 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.