As the weather cools and even when we get to freezing temps, the bug activity will slow down and that can also mean the bite slows down. Trout are still feeding though, they will continue to pack on the calories to prep for winter, you just have think smaller at times. Dont be afraid to get into a run and switch flies a few times before moving on. I always start big, stonefly nymphs, bigger mayfly nymphs etc... then I start to down size. If you do see fish rising most likely they are hitting midges now, so small is key when it comes to dries.
Took a few hours on Saturday to enjoy the great weather. I just ran up the Black Smith quick and was up there from about 12:30-2:00. The time change and the longer shadows make the river mostly shaded by afternoon. The fish were not super aggressive. Not a lot of bug activity either for being a warmer day. The best patterns were again any nymphs with a hot head. Use pink or orange.
The Narrows has been fishing great still, reports to us have indicated though that there are quite a few other up the canyon fishing as well. Your standard nymph selection will still get it done up there. I always like fishing hot bead nymphs between the bridges.