Ga Tech has a Tech Trek program (ww rafting, rock climbing, caving) which students can do before or after their summer orientation program. They also have an optional Wreck Camp for freshmen a week before school starts that is setup like a summer camp.
To further expand on the mandatory vs. optional dichotomy… many schools have a mandatory group experience, but give students a choice of activities, some of which are outdoors and others of which are not. So, the outdoor adventures attract those who are so inclined, but everyone has a group experience of some sort, and gets to know others who share their interests. U of Puget Sound, for example, is known for its outdoor orientation trips but offers many other themes as well. The detailed descriptions, to which you can click through, show the variety offered : https://www.pugetsound.edu/student-life/orientation/
Penn. The outdoor pre-orientation program is called PennQuest but they also offer pre-orientation programs centered around leadership, community service, environmentalism, and the arts. Enrollment is capped and an application and program fee is required.
Colorado College.
https://www.coloradocollege.edu/offices/outdooreducation/priddy-experience/
https://www.coloradocollege.edu/priddymap/
I agree that a lot of schools could be included, but the program descriptions themselves can be interesting to browse. Hamilton offers hiking, canoeing, rock climbing, sea kayaking and mountain biking trips in areas in and around the Adirondacks.
https://www.hamilton.edu/firstyear/orientation/trips/adirondack-adventure
James Madison does an excellent job with freshman orientation:
https://www.jmu.edu/orientation/firstyear/1787.shtml
Here’s a sample schedule:
https://www.jmu.edu/orientation/_files/2019-Mappy.pdf
They also offer an outdoor Madison Orientation Adventure Trip (MOAT) the few days preceding actual orientation for those so inclined:
https://www.jmu.edu/recreation/activities/adventure/moat.shtml
UNH, UVM, Wheaton (MA), St. Lawrence