Ken I would suggest THE THUNDER OF THEIR PASSING by Robert D. Turner and THE CUMBRES & TOLTEC SCENIC RAILROAD by Spencer Wilson and Vernon J. Glover. They both provide a lot of historical background on the C&TSRR, and I especially liked the wonderful photography in Robert Turner's book. I love the C&TSRR and find Carlos website to be a great source of information on what's currently happening.