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 4501 at Helena, Montana, in September 1953. Number 4501 is a class Z-4 built by Alco-Richmond in 1923. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5006 at Helena, Montana, in September 1953. Number 5006 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 5121 at the coal dock in Helena in Montana, 1952. Number 5121 is a class Z-7 built by Alco-Schenectady in 1941. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 5125 at Helena, Montana, on May 22, 1951. Number 5125 is a class Z-7 built by Alco-Schenectady in 1941. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific 5133, a class Z-8, pushes on caboose 1012 to move a freight out of the yard at Helena, Montana, in 1953. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, helper locomotive, steel caboose.

Plat Map of Great Northern facilities at Helena, Montana, March 1, 1913, Sheet Number 1, Line Segment 713, showing the Great Northern fairgrounds spur.

Plat Map of Great Northern facilities at Helena, Montana, March 1, 1913, Sheet Number 2, Line Segment 713, showing the Great Northern, Northern Pacific mainlines, interchange.

Plat Map of Great Northern facilities at Helena, Montana, December 1, 1915, Sheet Number 2, Line Segment 713, showing the Great Northern, Northern Pacific mainlines.

Plat Map of Great Northern facilities at Helena, Montana, December 1, 1915, Sheet Number 1, Line Segment 713, showing the Great Northern, Northern Pacific mainlines.