A set of trim power at UP's West Colton departure yard performs some switch moves near Pepper Ave.

It's a busy day in the Union Pacific's North Yard in Denver. Changing out track in the middle of an operating yard is challenging at best, with track maintenance vehicles jockeying for position a... (more)

UP 1610 (SD40N) works the North Yard after a night of heavy snow.

UP 1598 (SD40-2 which has been rebuilt to a SD40N) is sorting a cut of hoppers while UP 5087 brings another train into the yard. If you look closely in the background you can see a BNSF train wai... (more)

UP 1624 (SD40N) struggles to pull a long cut of cars out of the UP North Yard for sorting.

UP 1842 (SD40-N) and mate get ready to sort some freight in the UP's North Yard.

Taken with permission.

A variety of engines wait for servicing in the UP's North Yard while UP 1640 (SD40N) continues to sort freight cars.

The Union Pacific Wendover Local runs every day except Sunday to service the many mineral extraction, ore loadouts and hazardous waste facilities on the shore of the Great Salt Lake and on the Bon... (more)

The remote control operator of UP 1640 (SD40N) sends a long freight south of the North Yard so that the individual cars can then be sorted.

UP 1826 (SD40N) sorts a cut of oil cans in the 36th Street Yard in Denver.

UP 1640 (SD40N) and mate work the North Yard in Denver sorting freight cars while UP 3922 (SD70M) gets ready to lead two other power units and a long freight out of the yard.

UP 1826 (SD40N) works the south end of the 36th Street Yard in Denver.

A freshly painted UP 1842 shows off the new colors in the UP's North Yard. She started life as an SD40-2 but was rebuilt with an SD40N designation.

A variety of light units work the UP North Yard in Denver, including UP 712 (GP38-2), UP 1826 (SD40N) and UP 1422 (GP40-2)