Northern Pacific steam locomotive 4501 at Butte, Montana, on August 19, 1949. 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 4501 at Butte, Montana, on August 19, 1949. 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 4500 at Butte, Montana, on August 19, 1949. Number 4500 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 4500 at Butte, Montana, on August 19, 1949. Number 4500 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 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 36 at Butte, Montana, on August 19, 1949. Number 36, a class Y built by Schenectady in 1898, poses with its rods down at the roundhouse. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 36 at Butte, Montana, on August 19, 1949. Number 36, a class Y built by Schenectady in 1898, poses with its rods down at the roundhouse. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 35 at Butte, Montana, on August 19, 1949. Number 35, a class Y built by Schenectady in 1898, is coupled to a Burlington Route stock car in the yard. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight yard, stock car

Northern Pacific steam locomotive 35 at Butte, Montana, on August 19, 1949. Number 35, a class Y built by Schenectady in 1898, is coupled to a Burlington Route stock car in the yard. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight yard, stock car

Northern Pacific steam locomotive 29 at Butte, Montana, on August 19, 1949. Number 29 was built as a class Y-1 by Schenectady in 1899. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, wood box car, freight yard