It’s time to use terrestrial patterns on the upper river. Caddis swarms and AM diminishing spinner falls still happen, but those ant, beetle, horsefly, and hopper patterns seem most effective. Want to fish Box Canyon? During daytime you will share it with innertubers and rafters. So fish there very early in the day or fish from dinner time to twilight. Bead head nymphs and terrestrial patterns presented tight to the bank still work. On overcast days any kind of big stonefly nymph will attract interest.