David, nvr2l8 is right on about the best fishing being up high, but don't think you have to run all the way up the mountain to catch fish. I fish a couple evenings a week, during summer, within 20 minutes of Townsend, and still catch quite a few fish. A good rod to bring would be an 8.5 foot 4 weight. It will fish anywhere in the park. But everyone has opinions about what they prefere. I personally use a 7.5 foot 3 weight for most my fishing. You may want to checkout http://www.tiptoncabins.com/index.html for a cabin rental if you're looking for the Townsend area.
My posts are worthless without pictures