The Yellowstone is sliding nicely into fall mode, according to the September 14, 2026 report by Yellowstone Angler, with flows down to 1,710 CFS, cooler 55–62° water, and trout starting to act like they know fall is happening.
Hopper fishing has perked up enough to bring some quality fish to the surface, but the bigger notice is browns getting increasingly interested in a well-swung chunk of streamer, prompting Yellowstone Angler to declare, “It’s officially streamer time!”
The one “wrinkle”, for lack of a better word, is the wind, especially downriver where gusts could hit 55 mph, though the valley looks less rowdy and the rest of the week should mellow out.
Basically, keep hoppers and ants handy for opportunistic dry-fly eats, nymphs in the bullpen, and don’t be shy about throwing olive, black, or white streamers when hunting the river’s heavier residents.
Good luck out there!
Ready to talk flies, river conditions, or line up your next day on the Yellowstone? Give Yellowstone Angler a call at 406-222-7130, email staff@yellowstoneangler.com, or swing by the shop at 5256 US Highway 89 South in Livingston, Montana. The shop is open Monday–Saturday from 7:00 AM–5:00 PM and Sunday from 8:00 AM–4:00 PM.
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