Byers Canyon wood
I bet this is an ever-present situation, but after the big drop, make sure you get right as there is a huge pile of wood on the left. There is plenty of time to get right, but a swim or a few missed rolls could be really bad. There is a lot of water going through the pile. Also, we missed the pile from both our roadside and river level scouts somehow, so make sure you at least know where it is.
On a brighter note, Byers was a very pleasant surprise. Big water class IV at 1800cfs with huge waves and no holes down the gut. It's short but takes only 50 minutes including shuttle.