Sometime after WW2 it was nationally agreed that all bridges should be painted aluminium and not black which was quite common at that time. The reason was to cut down on car accidents by making the bridges more visible at night. Why this should also apply to RR bridges I do not know but apparently it did. There are quite a few photos of the D&RGW bridge out of Durango painted black in 1947 and alongside it the road bridge carrying US 160 painted aluminum. Three years later another photo has them both in aluminum.
Gato - the track, buildings and gon - is on Southern Ute Reservation land and fenced off from the road with warnings to would be trespassers. The gon is still there because it developed a hot box on one of the last trains east. The water tank collapsed on a windy saturday in June either 2005 or 2006, can't be certain which. But here it is a couple of years before it fell.
The east and west San Juans passed at Carracas Siding.
Mark K