Originally Posted by rivervibe
I'd say Desolation Canyon. It goes right through the Canyonlands NP with the Needles District right there on your right. There is also the Goose Necks of the San Juan to look into.
Deso is actually pretty far upstream of Canyonlands and more in N. Utah. I think vibe's thinking of Labyrinth Canyon which is a beautiful Class I flatwater float from Green River UT to Mineral Bottom, just outside Canyonlands NP. Deso also requires a permit which can be difficult to get at this stage of the game, however the 30-day payment deadline is coming up and that's when lots of permits get cancelled and go back into the system.
For showing up without a permit the Colorado from Cisco to Moab would be a good option at that time of year, and the Dolores may have water in it. You may be able to get a San Juan permit for a small group a couple of weeks out.
Cataract will be at cranking about then and you'll want to be ready for game-on big water action there. I've never run it but have heard a lot of pretty harrowing stories about high water Cat trips so you don't want to take it lightly.
Have a good trip!