Northern Pacific steam locomotive 4021 at Missoula, Montana, on June 08, 1955. Number 4021 is a class Z-3 built by Alco-Brooks in 1920 J.M. Fredrickson collection. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 4021 at Missoula, Montana, on June 08, 1955. 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 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 402 at Butte, Montana, circa 1902. A crew member poses on Number 402, a class D-6 built by Rogers in 1899, at the engine facility. She was formerly St. Paul & Duluth Railroad No. 65. Photo by R.C. Lean, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, 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 4004 at Helena, Montana, circa 1920. Number 4004, a class Z-2 built by Baldwin in 1910, is posed with its crew. Photo by Keller, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4004 at Helena, Montana, circa 1920. Number 4004, a class Z-2 built by Baldwin in 1910, is posed with its crew. Photo by Keller, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4003 at Bozeman, Montana, on August 22, 1943. Number 4003 is a class Z-2 built by Baldwin in 1910. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4002 at Bozeman, Montana, on August 22, 1943. Number 4002 is a class Z-2 built by Baldwin in 1910. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 4001 at Livingston, Montana, on August 22, 1943. Number 4001 is a class Z-2 built by Baldwin in 1910. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo