UP 5848 & 7690 power a westbound stack train.

Union Pacific’s west local has just come off of Rocky Spur and slowly heads east on the main while a westbound coal train passes on the siding at Rocky, Colorado, on March, 16, 2011.

The UP 5848 begins to move at light speed as it accelerates a coal train over the BNSF mainlines at Santa Fe junction.

A westbound Union Pacific coal train climbs through Clay, Colorado, on the sunny afternoon of March 16, 2011.

A westbound Union Pacific coal empty curves out of Rocky siding, of which, Little 10 Curve is a part of, on a dry March 16, 2011. Clay siding is in the foreground, and the train will be here in a ... (more)