I don't know if Dartmouth has ROTC programs.  If you have AFROTC, look into that.  AFROTC commissions about 1300 people per year, with about 500 available pilot slots.  If you join AFROTC, make sure you get good grades, do well on PT tests, and get a good commander's review.  Pilot slots are competitive, so the higher you rank on the order of merit (which is based on what I said above) the higher the better your chances of getting a pilot slot are.  The order that people apply for jobs is the order of merit, so if you rank #1, you get to pick first. 

www.afrotc.com has the official information