That is indeed the top / end of the Monarch Pass branch, where loaded limestone trains were assembled for the trip down to Salida and the rotary dumper. The two outfit cars were set out to serve as shacks for the car inspectors who looked over the gondolas before the trains departed. The car in the foreground is D&RGW 04953, in the background is D&RGW 04951.
Happily, both outfit cars are still with us, though far from Monarch Pass. D&RGW 04951 is in Oregon and D&RGW 04953 is here with me in Kansas.
D&RGW 04953, Bendena, Kansas September 25, 2022
Jason Midyette