Seems like everything is hatching and all the fish are eating, especially in the float section of the river. Salmonflies, Goldenstones, Morning PMD's; and in the afternoon, caddis. If you stick with the big bug you won't get many, but the ones you land will be larger. Go with caddis and you will get more action witht the smaller to medium sized fish. Last week the releases from Hebgen were down to 500cfs, which is very low. Extra stress on the fish resulted and fishing got tough. Slowly the water flow was increased and now the river is at 843 coming out of the dam. The fish are much happier now and fishing has greatly improved. Now fishermen are seeing green drakes out there.
Good hatches and good dry fly fishing can be found on this river. Salmonflies around the Taylor's Fork section. Big Goldenstones have also been seen downstream of the Taylor's Fork. PMD's have been in the mornings from 10am to around 2pm and lots of caddis all afternoon. Try sizes #14,#16 tan in color.
This lake is fishing well, it's been best in the mornings because in the afternoons the wind has been pretty strong. Midges early on and then the callibaetis get going about 10am. This hatch peaks around noon or 1pm. You will also have damsels size #10. Olive X-mas tree buggers #12 have also produced fish.
Madison and Firehole River
Too warm and slow fishing. This is the place to give the fish a break free from the pressure of the fishing as they deal with the heat of summer. The Gallatin, Gardner, Yellowstone, Lamar, and Slough are the go to places for fishing now and the waters are much cooler so there is little pressure on the fish.
Gallatin, Gardner, and the Yellowstone River
SALMONFLIES! Need I say more!??
Lamar River and Slough Creek
This area has really shaped up in the past week. Bugs are starting to hatch and there is more action to be found because of this. Both Green and Gray Drakes are going, but best on cloudy days. PMD's will be hatching from 10am-2pm. You will see Caddis throughout the day hatching and then in the evenings they will come back to the water and lay their eggs. As you head out to enjoy the fishing here, don't forget your ants and beetles as terrestrials are always good to have with you during this time of year.