You can't carry at a public school, however you can bring your gun but it must remain in the glove box of your car and the doors locked. I know some schools allow Concealed carry but it is probably debatable since CSU just recently banned concealed carry but then a lawsuit was filed on them and as of right know I believe the ban has been dropped. check out RMGO.org they keep updated on all laws in the state of Colorado and you can ask them any question and they will give you a straight answer.