Yellowstone-area trout settle into a quiet fall rhythm

What's biting

What's next

Expect the new moon to keep nights dark and mornings cold. Cold starts mean fish are slow to move, so plan on late morning through mid afternoon, when the sun has warmed the water a touch and any hatch tends to fire. Baetis and midge activity typically peaks on overcast, damp days, so a cloudy forecast is better than a bluebird sky.

Per Trout Unlimited, weight matters on a nymph rig. With the river in a settled fall stage, add enough split shot to get your flies into the strike zone, and shorten up if you start snagging bottom. Per Reno Fly Shop, small patterns like a zebra midge, a Perdigon or a pullover BWO are good choices for tailouts and slower seams. Caddis Fly (OR) also calls the Perdigon a hot fly this fall.

Brown Trout in spawning mode will also eat streamers and egg patterns. Flylords Mag notes that an Atomic Egg is easy to tie and works when trout key in behind spawning fish. If you see redds, stay off them and fish the water below. Check state regulations and any seasonal closures before you go.

Context

Early to mid October in the Yellowstone and Snake country of Wyoming sits firmly in the fall transition. Summer terrestrial fishing is over, hatches shift toward small mayflies and midges, and the first hard frosts push fish out of the shallows and into deeper runs and softer water. Crowds thin out considerably after Labor Day, which makes this one of the quieter windows to fish. Flows typically settle as irrigation draw-down ends and tributaries clear, so the water is often at its most fishable of the year. Lake Trout in the larger lakes also move shallower as fall cooling proceeds, though stream fishing usually gets most of the attention.