I'd argue that for any heritage railroad property, when you talk of "Preservation", you must be specific of the context and time period. Remember that Preservation is an on-going activity. For the C&TS, it didn't stop when the states wrote D&RGW a check for the property. In the years since, you could argue that had there had been many champions to step forward and show passion for keeping it going.
The stages I can think of for the C&TS:
1. Initial awareness that it is special (pre-1968)
2. Initial action, lets try to save it
3. Ok, so now we have a railroad, how do we run it?
4. Hey, all it takes is a Sugar Daddy
5. Oh @#$%&, wood rots, metal rusts, how do we keep what we have?
6. Volunteers will try to save the day
7. Back to the Drawing Board
Someday someone smarter than I will come up with a better list. I didn't assign dates because some of these overlap, and I don't want to start arguments and nit picking.
I'd argue that for each time period, there's going to be a person that we can look back at and say that if they didn't do what they did, the thing wouldn't be here today. Besides, those identified already in other posts, my nominations include, Bob Keller, Willis Kyle, Spencer Wilson. There's others pending that are still alive. Plus don't forget all of the employees of the railroad.
It's taken a lot of effort by everyone. But if it hadn't been, it would be the world's most scenic 64 mile long hiking trail.
Bill Kepner