I remember that they are fairly limited in the number of incoming students who can sign up. The information about the trips come late in the Spring along with all the other piles of Orientation info and it was first come first served.
I'm pretty sure you can do similar activities later on, in fact, you can get a start as part of satisfying your P.E. requirements and then if you like it, sign up for more.
My D, who's a freshman, had planned to go on the second of the two pre-orientation Wilderness Adventure trips this past August, but then cancelled when she found it partly conflicted with tailend of the Cove community service project she had also signed up for and would also mean missing a last week with her HS boyfriend.
When she was home for Winter break she was talking about taking one of the Outdoor Education Classes in the Spring. They sound pretty awesome to me.
Here are some of the current ones:
http://www.colgate.edu/DesktopDefaul...1481&pgID=5635.
If you go up for a visit, you can visit the Base Camp (the Outdoor Ed Office) on campus and learn more.