Flintstone and the put-in camps are both impacted. That river is seeing increasing traffic even with the small flow window. Good suggestions above on ways to minimize the damage--we need more of that kind of behavior on the river in general.
Nobody mentioned another way we kayakers impact wilderness rivers--dragging our boats. It's real tempting on those domes, and it's introducing totally synthetic materials to a wilderness. At least poop, tp, and fires all biodegrade... eventually. I'm certainly not beyond reproach for dragging boats in wilderness areas, but it's something to think about. Pretty jarring to come across a big blue smear on a rock in the middle of otherwise pristine country. Yet its a common sight on many of these class V multidays.
"A river is more than an amenity, it is a treasure."
-Oliver Wendell Holmes writing for the majority in New Jersey v. New York