Take the WHOLE trip!

Since you've decided to go ride the C&TS, make sure that you take the through trip and come back by bus.
Ride the train from Chama. Doubleheader or not, this is one incredible ride. A mile or so out of Chama the throttle(s) get(s) pulled all the way back tot he tender and is left there all the way up the hill.
But make sure that you ride all the way to Antonito. Once past Los Pinos (a few miles east of Cumbres) you leave the highway behind for the rest of the trip, and you get the feeling that you are going someplace that no one else has ever seen.
You won't be disappointed.