Four locomotives on a trestle bridge in Colorado, circa 1925. J.M. Fredrickson collection. Other Subject Classes: steam locomotives, bridge

Georgetown Loop Railroad bridge at Georgetown, Colorado, circa 1985. Train on the high bridge on the loop at Georgetown. Photo by J.M. Fredrickson. Other Subject Classes: bridge, passenger train

Manitou & Pike's Peak Cog Railway steam locomotive number 3 at Pike's Peak, Colorado, circa 1950. Photo from J.M. Fredrickson Collection. Other Subject Classes: steam locomotive, passenger train.

Missouri Pacific Railroad dome passenger car "The Eagle" during a station stop at Pueblo, Colorado in 1959. Jim and Tim Fredrickson pose for the photobgraph. Photo by J.M. Fredrickson. Other Subject Classes: passenger car

Northern Pacific 50-foot, single plug door, insulated refrigerator car 96158 is in a yard at Denver, Colorado, on October 18, 1982. The car is part of the 96000-96199 number series. Photo by GJ Werkema. Other subject classes: freight car, refrigerator car

Northern Pacific 50-foot, single plug door, refrigerator car 97836 is in a train at Denver, Colorado, on February 11, 1990. The car is part of the 97800-97899 number series. Photo by GJ Werkema. Other subject classes: freight car, refrigerator car

Northern Pacific box car 1005 on a yard track in Denver, Colorado, no date. Box car NP 1005 was built by Pullman Standard in 1945 as part of the 29000-29499 40-foot box car series. In 1954, NP 1005 was one of 10 cars that had Evans DF Loader Systems installed, given a green with white strip paint scheme, and renumbered to 1000-1009. Photo by GJ Werkema. Other subject classes: freight car, steel box car

Northern Pacific box car 1125 in a cut of freight cars in March 1975 in Broomfield, Colorado. Box car NP 1125 was built by the NP Car Shops in Brainerd, Minnesota in 1950 as part of the 31000-31499 50-foot box car series. In 1955, NP 1125 was one of 150 cars that had Evans DF Loader Systems installed, given a green with white strip paint scheme, and renumbered to 1100-1249. Photo by GJ Werkema. Other subject classes: freight car, steel box car

Northern Pacific 40.75-foot, box car number 15529 with one sliding door is in a yard at Denver, Colorado, on April 10, 1965. The car is part of the 15500-15999 number series. Photo by GJ Werkema. Other subject classes: freight car, steel box car

Northern Pacific 40.75-foot, box car number 17410 with one sliding door is in a yard at Longmont, Colorado, on June 7, 1978. The car is part of the 17000-17499 number series. Photo by GJ Werkema. Other subject classes: freight car, steel box car