Coming a bit late to this thread, but I would suggest that your son take a look at Williams. It’s very selective for sure, but they like applicants with a combination of academic accomplishment and a passion for outdoorsy activities, and who would consider Williams’ insular mountain village location a big positive.
Williams has a high level of participation in its Outing Club and nearby access to a wide range of activities, e.g.,climbing, hiking, camping, skiing and snowboarding and generally lots of opportunities to enjoy being active in a beautiful mountain environment.
Williams does have a cycling team, but it appears to be more informal than competitive. (Not my area of expertise.)
https://sites.williams.edu/cycling/prospective-athletes/
Williams sciences, notably chemistry, biology and geosciences, are excellent across the board and there is a good deal of synergy between Environmental Studies and other sciences.
The Center For Environmental Studies “manages the Hopkins Memorial Forest, a 2600-acre natural area located 1.5 miles from campus, in which there are field-study sites and a laboratory.”
I would also note Williams’ generous funding for summer research projects. You can see a list of past projects on the Center for Environmental Studies site: