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)

Two SD40Ns run light through CP784 towards Grant Tower in Salt Lake City. Behind it is an extra run of the MGRRO which arrived in North Yard mere minutes before from Green River, Wyoming.

Conductor of UP 1798 South inspects the running gear of the repaired tank cars in his train as they move through the switches in the yard at Chico, TX.

In the UP North Yard, I spy with my eye, a bloody nose Southern Pacific, a former SP MP15AC, a blue Smurf GATX, a former Missouri Pacific GP38-2 and a rebuilt SD40N.

The setting evening sun lights up the face of a new SD40N rebuild. The crew has taken the advantage of the snoot nose to store about a months worth of bottled water.

I can imagine that the remote operators for the engines in the UP's North Yard in Denver likely had HO or Lionel train sets when they were kids. Here a remote engineer pulls a string of cars out ... (more)

A six-pack of UP light power sits under the pedestrian overpass that spans the 36th Street Yard. A great place to watch trains if your in the Denver area.

UP 1950 rests before making the trek to Chicago, IL.

UP 1950 waits to take some empty sand cars south towards Chicago, IL.

With a couple friendly toots from the passing coal train, the pull down works the west end of Global 3 with two SD40Ns. The C&NW twins can barley be seen in the distance.

UP 1967 pulls a cut of cars out of Butler Yard in Butler, WI.

UP 1640 works a frozen 36th Street Yard in Denver.