Lots of choices to pick from. Ennis is some of my old stomping grounds. You might investigate the "canyon" area below the dam on Ennis Lake. It's been a long time since I was there but the browns and rainbows use to be stacked in the pools there. But watch where you put your hands. There's some badass snakes in that area. I've only fished it during the elk season and never in August. The water might be a tad low in August. Too much good water in that area to do much in half a day...... If you have the money, look into fishing Odell Creek. It's private and the browns (all wild) will average over five pounds.