UP 1957 (SD40-2) waits on the ready track by the tank cars in the Union Pacific's North Yard in Denver, Colorado.
Light power group together in the North Yard in Denver, Colorado.
UP 1957 (SD40N) works the Union Pacific's North Yard in Denver, Colorado.
UP 1957 (SD40N) works the North Yard in Denver, Colorado.
UP 1957 (SD40N) works the North Yard in Denver, Colorado, sorting a line of freight cars.
It is a light day in terms of Union Pacific motors at the North Yard in Denver, Colorado.
UP 1957 (SD40N) brings a short cut of cars through the refineries in Commerce City, Colorado.
UP 1957 (SD40N) and UP 1640 work sorting a cut of cars in the Union Pacific's North Yard in Denver, Colorado.
UP 1957 (SD40N) gets ready to pull a string of freight cars out of the ladder for sorting in the North Yard in Denver, Colorado.
Union Pacific heavy and light power populate the UP's North Yard in Denver, Colorado.
UP 1957 (SD40N) shuffles a load of coal in the North Yard in Denver, Colorado.
UP 1957 (SD40N) sorts a cut of cars in the Union Pacific's North Yard in Denver, Colorado.
