Wow, great images John...If I saw these before I don't really remember them, especially the 3031 shots, which are pretty choice!! I was lucky enough to see every aspect you photographed on on 1963 trip, NG 100% steam, UdeY at Merida, The Electrics, and some standard Gauge, although not much trackside views like yours.
Tom pointed out that the SG was pretty much nearing an end in 1968, but there was still activity. I know a guy who went in 1969 and got them to steam up engines at Mexico City, and he ran them around the yard, so I know there was some activity that late, albeit odd like his stuff.
My point was that in the days of steam there was so much to do, and so many good choices that one could not do it all. Sure today one can go see anything they want as far as tourist ops(albeit during the seasons), but regular service steam had the clock ticking down to extinction in the 50's. Had 1968 been 1972, when I made my first overseas trip for steam, I might have elected to do Mexico instead of the Rio Grande NG, or better yet do Mexico, and the NG on the way home.
But given the 1968 trip was a family vacation, and one of the last we ever took together, I can see why it was done the way it was. It is just interesting to note that regular service steam in Mexico could still be seen in 1968 as well as the last of the Rio Grande NG. Of course Mexico might have been a bit more difficult than even the remote D&RGW was back then.
Anyway thanks for the images. Do you have any more than the few you had on Mexico. Would love to see more!
Greg