Yellowstone River (4,320 CFS at Corwin Springs)
The Yellowstone could possibly be at its very best this year. The fishing has been incredible throughout the entire river, and throwing whatever type of flies you enjoy fishing. The dry fly bite has been fantastic most days, and the nymphing still continues to produce great fish. I have been bobber fishing in the mornings, and throwing hoppers during the mid to late day.
Madison River (1,300 CFS at Cameron, 1,590 CFS below Ennis Dam)
The Madison is still fishing quite well. Nocturnal stoneflies, small terrestrials, and caddis (Spruce moths up high) are all producing for the fish looking up. Sculpins and zonkers fished underneath. The Lower Mad is pretty warm, and full of recreational floaters, so go somewhere else. Just about everywhere else is a better option anyway...
Missouri River(4,360 CFS below Holter Dam)
The Mo is still fishing well, particularly early in the day. The trico thing is still hanging on, and you can always fish a Bloom's ant and catch a bunch. The fish are a little tougher later in the day, but the Mo is still a great option.
Gallatin River (699 CFS at Gateway)
The Gallatin is really fishing well right now. Spruce moths, caddis, and nocturnal stones are moving a lot of fish in the canyon, and the hopper thing is picking up closer to town.
Jefferson River (533 CFS at Twin)
The Jeff is pretty warm right now, temps hovering in the low 70's, and probably not a great option. Watch for the temp to come down, and then head on over.