Long Colorado Weekend Trip

Hey everybody! I just booked flights to Denver for a long weekend over 4th of July (Friday, June 30-Tuesday, July 4). I fly into Denver but will rent a car and head out somewhere. I'm hoping to spend the majority in the mountains (whatever activities keep me in nature). I live in Indianapolis (extremely flat) and am really hoping to escape/relax for a few days. I'm looking for suggestions on smaller towns/cities that offer access to trails, have unique scenery or some other appeal. I've heard Ouray and Aspen are gorgeous but wanted to see if anybody has done a shorter trip like this. :) Thanks!!