As the blue hour settles over Denver, Colorado, on December 7, 2015, Union Pacific GE AC4400CW-CTE No. 5687 sits inside the cavernous main hall of the former Rio Grande backshop at Burnham Shops. No. 5687 is getting an overhaul and a change out of its old 4,400 hp 7FDL16 prime mover. In a place that once built and rebuilt steam locomotives, this unit is the last locomotive to be overhauled at Burnham before UP closed up the place on February 14, 2016. On the left, UP EMD SD70M No. 4524 is getting PTC installed.