Cadster has it right, I used to guide flyfishing/row dory's on that stretch for 7 years.. It's a super easy/mellow float. -especially after mile 15 or so.. Red Creek rapid is the only one you might have to watch out for bc of length and rocks at 800 cfs. Some guides would make their clients walk around the rapid on the obvious river left trail, while they took the drift boats through at 800..it gets pretty thin/rocky with fast water.
camping on the B section below the damn is first come/first serve, but you still have to reserve a site with the little hole camp people.. after that, I believe you can camp in any of the sites downstream of the sec. B take out at Indian crossing..-those camp hosts might know the Beta on camping in the refuge..
in any case.. bring a flyrod bc you'll see more trout than you've ever seen in your life.. and they get huge down below red creek rapid, and thru the refuge..
beautiful float.. gin clear water... ~Mike