A crew member walks out to UP 1640 (SD40N) and will get the motor moving into the North Yard to sort freight cars.

UP 1640 (SD40N) works the North Yard in Denver, Colorado.

UP 1640 (SD40N) waits in the Union Pacific's North Yard in Denver, Colorado for orders to sort cars.

A variety of light and heavy power wait for servicing at the North Yard in Denver, Colorado.

UP 1640 (SD40N) works the North Yard in Denver, Colorado.

A set of UP motors runs through the North Yard in Denver, Colorado.

UP 1640 (SD40N) and mate have the yard to themselves as they work on sorting freight cars into the ladders of the North Yard in Denver, Colorado.

UP 1640 (SD40N) moves into the North Yard as the sun sets over the Rocky Mountains.

UP 1640 (SD40N) joins a variety of UP power at the servicing island in the North Yard.

A trio of SD40's are at the ready in the Union Pacific's North Yard in Denver, Colorado.

UP 1640 (SD40N) and UP 1344 (GP40-2) wait in the North Yard in Denver, Colorado for orders.

UP 1640 (SD40N) moves through the BNSF's Denver Yard after dropping off a cut of cars.

UP 1640 (SD40N) works a cut of cars in the Union Pacific's North Yard in Denver, Colorado.

UP 1640 SD40N sorts oil cans in the North Yard as a pair of BNSF motors arrange a stack track in the adjacent intermodal facility.

UP 1640 is one of many SD40N units that can be currently found working the North Yard in Denver.