Bighorn River fishing continues to be a solid option for some fall fly fishing in Montana.
Nymph fishing with typical Bighorn rigs has been solid in the deep, fast water while floating. Tandem nymph setups with a San Juan and a small mayfly nymph dropper are a guide standard right now. An overall leader length that is 8-10' from the bottom fly to the indicator has been key to finding those bigger rainbow trout in that heavy water.
Fish are still eating some dries, but they are in the slow water and presentation is everything when imitating spinners or pseudo duns.
Running a caddis dry along the inside seam of a riffle is a good way to prospect a run with a dry, before settling into the indicator game while wading.
Expect some issues with weeds as the cooler water has them breaking up, more and more.
Red San Juan Worm
Black Lite Brite Perdigon
Frenchie
Peacock Elk Hair Caddis