The fuel tracks are quiet on the night of December 22, 2012, at Union Pacific’s North Yard locomotive facility in Denver, Colorado.

UP cyclops 2317 (SD60M) waits in the North Yard for the call to service.

UP 2317, a SD60M 'Cyclops', waits for assignment in the North Yard.

A pair of Union Pacific SD60M's and a four axle Geep idle at UP's 36th Street Yard in downtown Denver on a crisp, January morning in the mile high city.