The following report is by Fins and Feathers and scores a 2/5 for fishing:
Current Conditions
The Bighorn River is fishing steady right now. Most of the action is subsurface with hatches fading, but conditions are good enough to keep anglers into fish throughout the day.
Nymphing has been the most consistent. Sowbugs, scuds, and wire worms up top followed by small perdigons, prince nymphs, or zebra midges have been a reliable setup. Working these through pocket water and slower runs has kept rods bent.
Streamer fishing is improving. With weeds thinning out, browns are showing more interest, especially during low-light windows. Dark sculpin patterns, sparkle minnows, and streamers with a little flash are moving fish both in deeper water and along structure.
Dry fly fishing has slowed, but there are still a few midges and small mayflies around. The banks can also be worth prospecting with ants or beetles on calm afternoons, though rises are far from steady.
Overall, the Bighorn is a good choice right now. Nymph rigs remain the most reliable, streamers are starting to produce bigger fish, and the occasional dry or terrestrial is still worth a try when conditions line up.
Stream Flows
Flows
Recommended Flies

Gray Gonga

Black Lite Brite Perdigon

PMD Crackback

Black Zebra Midge

Orange Scud

PMD Jigster

Tailwater Sowbug

Skiddish Smolt