I don't think the most Coloradoans want to give up their favorite spots!
It's not true boondocking, but darned close. Dry camping at Williams Fork Reservoir. The capsit are open and not too on top of each other. Large trailers can get in with no problems, and you can pull up onto the beach in some places and right next to the water in others. There is also a dump station on the way out, but no fresh water available.
Williams Fork Reservoir