My daughter Logan and I floated the mainstream Bitterroot four days ago as it was on the drop, a bit too high for solid fishing. She did stick a big brown trout looked like, but he popped off before we got a visual. There is some fishing in side channels. A couple of days prior the upper root was also coming into shape but the the last couple of real hot days have it bumping again. It looks pretty muddy today, which is typical for late May/ early June. It can shape up quickly.
So really right now the MO is the best fishing choice! I have friends guiding the MO currently and the nymphing is solid. Typical spring bugs, pheasant tails, sow bugs, fire beads, and there is some dry fly fishing when the sun isn’t beating down on you. Short leashing or my preferred fishing /hopper dropper/ is working. One has to keep an eye on the Dearborn, it finally dropped and the lower river is fishing, but the hot weather might have an affect on things below the confluence if it bumps. I’m thinking we should be good there.
Keep your eye on Rock Creek, salmon flies started showing up so when flows drop a bit the creek should be awesome on the monster bugs! If you can find some side channels to fish up there, fish a San Juan worm or a Pats stone under a chubby or an indicator. The wading at high flows is sketchy so always be careful on that river.