As usual, Gerry has some great advice. To answer the earlier question, after you get above the cascades on the Middle Prong Trail, the stream is very close to the trail and access is much simpler.
I fished above campsite #18 a couple of times last year. In May I caught a dozen or so frisky rainbows, by July I hardly saw a fish. Hopefully they made it through the drought. If so, it should be a great place to fish. But make sure you are sneaky. I caught four of them in one pool by hiding behind a tree and flicking my line out to the edges of the pool (no backcasts).
Left side, right side...I knew I was doing something wrong with the Browns...