Northern Pacific steam locomotive 21 at Billings, Montana, on August 17, 1949. Number 21, a class Y-1 built by Schenectady in 1900, is shown with a cut of cars in the yard. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight yard, railroad crew

Northern Pacific steam locomotive 21 at Billings, Montana, circa 1950. Number 21, a class Y-1 built by Schenectady in 1900, awaits its next switching job at the Billings freight yard. Photo by Spear, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight yard

Northern Pacific steam locomotive 20 at Billings, Montana, on September 04, 1953. Number 20, a class Y-1 built by Schenectady in 1900, awaits its next switching job on a ready track at the roundhouse. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 20 at Billings, Montana, on August 19, 1949. Number 20, a class Y-1 built by Schenectady in 1900, is parked in the freight yard. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight yard

Northern Pacific steam locomotive 20 at Billings, Montana, on August 19, 1949. Number 20, a class Y-1 built by Schenectady in 1900, is traveling over a switch in the yard. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, freight yard

Northern Pacific steam locomotive 19 at Billings, Montana, on September 04, 1953. Number 19, a class Y-1 built by Schenectady in 1900, is stored out of service next to the coal dock. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, coal dock

Northern Pacific steam locomotive 19 at Billings, Montana, on August 17, 1949. Number 19, a class Y-1 built by Schenectady in 1900, is being readied for switching service. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 1711 at Billings, Montana, on September 04, 1953. Number 1711 is a class W-3 built by Alco-Brooks in 1913. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 1710 at Billings, Montana, on August 17, 1949. Number 1710 is a class W-3 built by Alco-Brooks in 1913. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive in roster photo

Northern Pacific steam locomotive 1077 at Billings, Montana, in November 1934. Number 1077, a class L-9 built by Baldwin in 1907, is parked at Billings. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo