Downtown Denver Railroads.
A sea of orange locomotives are seen sitting at BNSF Railway's Denver Diesel Shop, while an RTD N Line train passes on the flyover east of the yard. The flyover appears to only cross one track, which is part of a wye connecting the BNSF tracks to the UP tracks that the RTD A Line parallels. Of course, all of these lines then meet at Union Station just west of here anyways...
There are a few specks of other colors to be seen as well, including BNSF 9709 in the Executive paint scheme, KCS 4779, and a Ferromex locomotive that I can't quite read the number of.
Also of interest is a yellow and black Harsco Rail spreader, likely used for clearing snow in the winter, and one of BNSF's red and white fire trains, possibly strategically stationed in case the western wildfires spread.