Boulder reservoir has several good spots if you hike in from the west. There are a few areas on the Poudre outside of Ft. Collins, just drive up and look at the cliff walls. The canyon pulloffs on Bear Creek in between Morrison and Idledale. Up Highway 6 on Clear Creek outside of Golden before the first tunnel, then also between tunnel 4 and 5 I believe. Waterton Canyon has a bunch of spots too but it is a long hike just to jump.