Black Canyon of the Gunnison (actually the lower canyon in the Gunnison Gorge Conservation area) ! Famous for it's beauty, big trout and their famous salmon fly hatch. Really check skill set requirements for that run. (It's labeled "experienced rafters") It's a 14 mile run with class II and III rapids. I don't know what you have to do to get a campsite or if you have to go with a river/fishing guide to have access. Personally...I would go with the guide so I don't have to worry about anything more than fishing. It's on my bucket list for sure. Best do your homework if your going to do something like this on your own. Black Canyon Anglers is a good place to start. There are others too...as well as the National Park Service and Conservation Authority.