Free Resource · Updated 2026

Yellowstone River Fly Hatch Chart

The Yellowstone River below Livingston is the longest free-flowing river in the continental United States. It runs through broad valleys and dramatic canyon sections, holding large populations of wild brown and rainbow trout. The stretch from Livingston to Big Timber is the most popular and accessible for wade anglers.

Brown Trout, Rainbow Trout, Cutthroat Freestone Livingston to Big Timber, SC Montana Current Month Highlighted

Yellowstone River Hatch Calendar — Quick Reference

About Yellowstone River

The Yellowstone is a big river and fishing it well requires understanding how trout position in large water. Most fish hold in seams along gravel bars, behind boulders, and in the slower water on the inside of bends. A drift boat gives access to the best holding water.

The Salmonfly and Golden Stone hatches in June are the marquee events. Runoff from Yellowstone National Park keeps the river high through May, but when flows drop in late May or early June, the hatches fire and the big browns become catchable. Timing this correctly is everything.

Summer fishing with PMDs, hoppers, and Trico spinner falls is excellent and consistent from July through September. Fall BWO hatches in September and October produce good dry fly fishing with very light pressure and excellent conditions.

See the full Montana Fly Hatch Chart for hatch timing across all of Montana's top trout streams.

Check Conditions Near Yellowstone River

What to Fish

Yellowstone River Key Hatches

Salmonfly and Golden Stone

June

The Salmonfly and Golden Stone hatches on the Yellowstone are world-class events. Both hatches can overlap in June depending on conditions. Fish the banks and structure with large dry flies or dry-dropper rigs during the peak window.

Recommended: #4-6 Stimulator, Golden Stone #6-8

Pale Morning Dun

June to August

PMDs hatch consistently from June through August on the Yellowstone. The morning window is the most productive, with spinner falls adding to the action in the afternoon. Fish flat-water sections and seams where trout can hold and feed without chasing heavy current.

Recommended: #16-18 Sparkle Dun, PMD Emerger

Hopper

July to September

Hopper fishing on the Yellowstone is exceptional from July through early September. The wide valley has excellent grasshopper habitat. Fish the banks from a drift boat or wade near grassy cutbanks. Large brown trout feed aggressively on hoppers throughout the day.

Recommended: #10 Parachute Hopper, Chubby Chernobyl

Blue-Winged Olive

March to May, September to November

BWO hatches bracket the Yellowstone season. Spring hatches in April coincide with warming water and hungry trout. Fall hatches in September and October are excellent during overcast afternoons. The river sees very light pressure by October and the fish are easier to approach.

Recommended: #18-22 Sparkle Dun, CDC Emerger

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