Trout on the Yellowstone are definitely looking up for a big dry fly to fill up on! Stonefly season is transitioning nicely into hopper season. I’m still leaning toward the stonefly colors, like gold or brown. Having said that, we’ve been catching fish on peach the last couple of days (peach is more a hopper color). The usual suspects are working for a dropper: prince, pheasant tail, hare’s ear, etc. Streamers are working well on the windy, stormy days. Green crystal flash wooly buggers seem to be working best. The big stonefly nymphs, like a girdle bug, are still producing fished under an indicator.
Rock Creek is fishing great on smaller stonefly and hopper patterns: Madam X, parachute hoppers, trudes, etc.