The setup in Sterling is something of an interesting one. This is the south (west) end of BNSF's Angora Subdivision, which started to the north in Alliance, NE. BNSF does not own any trackage west out of Sterling. For 23 miles between Sterling and Union, BNSF trains run on UP's Julesburg Subdivision. Interestingly, UP does not own any track west of Union, and in fact does not operate any trains west of Sterling. BNSF now dispatches the UP-owned 23-mile stretch of track. UP's Julesburg Sub continues east from Sterling and meets with the UP Overland Route in Julesburg, CO, 60 miles to the northeast.
In this shot, a BNSF coal load just had a crew change, and the outbound train is ready to depart west. The track(s) the coal train are on are still owned by BNSF. The track to the right is UP. The BNSF coal load will pull to the west end of Sterling to meet an eastbound coal empty before departing on the 23-mile of UP Julesburg track.