I live in Colorado and know quite a few people whose kids have gone to CU-Boulder and CSU. CU is better known, but my D will be applying to both (along with a number of OOS schools) and I would be perfectly happy with either one if it came down to those two. One friend has a D who is a senior at Fort Lewis and has been very happy there. My oldest D and her boyfriend are both at CU and have been happy with it, though D would have preferred a small LAC (too much $$).
Boulder is expensive, but you can definitely live there for less than $1000/month. The complex where D and her bf live has 2-bedrooms from $1300 and it is a very nice place. They do have to take a car or bus to campus, but the bus is quite convenient.