A buddy (ZBaird) just got off Gates and had some beta:
The ranger was a real stickler and hassled his group for a lot of the trip, make sure you're leaving clean camps and that your PFDs are all in good shape. No firewood gathering in high season so bring your own.
Be prepared to deal with ring-tailed cats raiding your camp - clean up food early and thoroughly, close coolers and keep on boats.
Headwinds on the flatwater were brutal - get on the water early on the last day.
Otherwise he said it was a great trip,
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse