UP 1837 (SD40-2) moves a flat car and an oil can deeper into the North Yard in Denver, Colorado.

UP 1837 (SD40-2) shuffles cars in the North Yard in Denver, Colorado.

UP 1837 (SD40-2) works the North Yard in Denver, Colorado.

A group of SD40's hold station in the Union Pacific's North Yard in Denver, Colorado.

UP 1837 (SD40N) sorts cars into the ladders at the Union Pacific's North Yard in Denver, Colorado.

The crew of UP 1837 (SD40N) comes in from the North Yard after sorting cars early in the morning.

UP 1837 (SD40N) pushes a cut of cars in the Union Pacific's North Yard in Denver, Colorado.

UP 1837 (SD40N) backs into a branch of the North Yard ladder to lash up to a string of cars that need to be sorted.

A tagged UP 1837 (SD40N) waits for orders to work the North Yard in Denver, Colorado.

UP 1837 (SD40N) shows signs that it might have spent some time in California before arriving in Denver.

The YLZ14 yard job usually builds the outbound ZLCLT stack train in the mornings at LATC. Thanks to that train departing west out of the yard to the Metrolink Valley Sub, this job uses yard power ... (more)

A snoot nosed SD40N works LATC in a scene that looks 20+ years older than it is, thanks to the spine cars on what'll become the rear of ZLCLT.

YLZ14 builds the ZLCLT with a pair of SD40-2 rebuilds.

YLZ14 works the east end of LATC as they build the outbound ZLCLT with a pair of SD40 rebuilds.

The YLZ15 yard job works the east end of LATC with a pair of SD40-2 rebuilds in the shadow of downtown Los Angeles. On the right, intermodal ISALB stops to get paperwork for operating on Metrolink... (more)