Hi @c1224994 ,
Last year I stayed at River Run and used the shuttle to travel to/from the conference centre. I've uploaded a map I found online a while ago (keystone-map.jpg) which may be useful.
The meals were served in the open air in a field located within the shaded area just above the words "mountain village" on this map. It was not too far to stroll back at the end of the day to River Run but you would not want to be on foot racing back and forth during the day. The shuttle was about every 15 mins, and only took 5 mins of actual transport, so if you had good timing with the shuttle, you would not need a rental car.
All the best,
Trav.