UPY 691 (GP15-1) gets busy moving cars in the UP's North Yard in Denver, Colorado.

UPY 577 (A 45 year old former Missouri Pacific GP15-1) puts some muscle into moving a cut of cars in the Union Pacific's North Yard in Denver, Colorado.

Tonight's Chevron local is a big one. Lead by GP15's UPY 613 and 637. The INPOA is on the far track.

UPY 577 (GP15-1) is sorting a cut of cars into the ladder of the North Yard in Denver, Colorado.

A set of power off a work train heads back to Mead Yard.

A pair of GP15-1s work hard to pull a string of loaded coke hoppers into the ArcelorMittal steel mill in East Chicago, Indiana.

UPY 577 (GP15-1) has just released a wood car into the ladder in the Union Pacific's North Yard in Denver, Colorado. The crew will lash up to another string of cars and repeat the process.

Union Pacific's Chevron local has shed it regular combination of A GP15 and GP38. For a pure lash-up of GP15-1's 661 and 573.

A bay window caboose is tucked in behind the light power sitting in the Union Pacific's North Yard in Denver, Colorado.

UPY 691 (GP15-1) makes smoke as it moves a cut of cars in the Union Pacific's North Yard.

UPY 557 is one of the many former Missouri Pacific GP15-1's acquired by the Union Pacific and one which has also seemed to allude the repaint and refurbishment shop.

Heading for the barn. The Chevron local has completed it work, and had got the clear to run back to Roper yard.

Lite power off a work train returns to Mead Yard as they pass the interlockings at Alameda and Del Amo.

A day after much of the Salt Lake Valley got hit with a foot of snow. The Chevron local nears Roper yard, after doing it's work at the Salt Lake refineries.