Fishing Report Updated September 5, 2021

This Yellowstone River fishing report is valid from September 5 until the next cold snap, usually around September 20. Our next report will drop when the weather changes.

The Yellowstone is fishing fair on hoppers, ants, and small mayfly-type attractors. Most of the fish eating on the surface of late have been small, but not all. Slender purple, pearl, and black nymphs in the #14-16 range have been producing as well, but mostly whitefish except in the fast, turbulent, bouldery areas (such as Yankee Jim Canyon or near Gardiner). Dead-drifted Zonkers have produced a few big browns.

Hatches will be better on gray days. A variety of small-medium mayflies are possible. Baetis are the most consistent mayflies, though on the Yellowstone you seldom need to match them precisely. Instead we’ve been running #16-18 copper Hazy Cripples to match the approximate size of just about all the mayflies popping now. During gray weather, fish a purple Hazy Cripple. If you’re seeing larger numbers of #12-16 rusty mayflies, opt for a Brindle Chute or Brindle Cripple instead of a hopper ahead of the smaller mayfly-style attractor.

Terrestrial fishing will be better when it’s sunny or partly cloudy. Small peach hoppers have been drawing some good eats. Rusty or bicolor flying ants have been getting more fish. Fishing the hopper ahead of the ant or a small mayfly has been our main rig.

Learn more about fishing the Yellowstone River (in Montana).

Learn more about our float trips, a majority of which take place on the Yellowstone.

Learn more about our Montana walk & wade trips, which in winter and early spring take place on the Yellowstone.

Yellowstone River Fishing Report – Relevant Links