Yellowstone River Wyoming Hatch Chart - Yellowstone Park
Northwest Wyoming, inside Yellowstone National Park. The Yellowstone River is the longest river in the park, flowing north from its headwaters in the Absaroka Range through Yellowstone Lake, then north through Hayden Valley and over the Upper and Lower Falls of the Grand Canyon of the Yellowstone, before continuing through the Black Canyon to the park boundary at Gardiner, Montana.
Not all of this water is fishable - but the sections that are rank among the most scenic and rewarding cutthroat fisheries in the American West.
The fishable sections
Upper Yellowstone - Yellowstone Lake outlet to Upper Falls (Hayden Valley)
From the outlet of Yellowstone Lake downstream through Hayden Valley to the brink of the Upper Falls - roughly 16 miles of broad, slow-moving meadow water. Wild Yellowstone cutthroat trout, averaging 14-18 inches, with larger fish present. This is catch-and-release, fly-fishing only water. The river is wide, clear, and deceptively challenging - fish are visible but selective in the flat, slow pools. Bison and grizzly bear are common along the banks. Fish quietly, watch your surroundings, and give wildlife a wide berth.
Black Canyon of the Yellowstone - Tower Fall to Gardiner
Below the Grand Canyon of the Yellowstone, the river re-enters a deep volcanic canyon before reaching the park boundary near Gardiner. This section - the Black Canyon - is trail-access only and sees a fraction of the pressure of the Hayden Valley water. Wild cutthroat and some brown trout near the lower end toward Gardiner. Expect solitude, challenging terrain, and aggressive fish that haven't seen many flies. The trail drops steeply into the canyon - plan for a full day if fishing the lower Black Canyon water.
The Grand Canyon of the Yellowstone - not fishable
The canyon between the Upper Falls and Tower Fall - roughly 20 miles - is not accessible for fishing. The walls of the canyon drop hundreds of feet to the river and there is no safe access to the water. Do not attempt to access the river in this section.
The park season on the Yellowstone River typically runs from the Saturday of Memorial Day weekend through the first Sunday in November. Check current Yellowstone National Park fishing regulations - a park fishing permit is required in addition to a Wyoming or Montana license. Specific sections may have additional rules. Regulations are updated annually.
Shop by type: dry flies, nymphs, Euro nymphs, hoppers and terrestrials, streamers.
Year at a glance
| Month | Primary hatches | Also carry | Typical sizes |
|---|---|---|---|
| Jan-May | Closed to fishing inside the park | - | |
| Jun (early) | Caddis, BWO | Stonefly nymphs, PMD start | 14-18, BWO 16-20 |
| Jun (late) | PMD, caddis, golden stone | Yellow sally, callibaetis on lake outlet | PMD 16-18, stones 8-10 |
| Jul | PMD, caddis, callibaetis | Early hoppers, tricos on flat water | 14-18 |
| Aug | Hoppers, tricos, callibaetis | Ants, beetles, PMD | Hopper 8-12, trico 20-22 |
| Sep | Hoppers, BWO, mahogany dun | Callibaetis, streamers (Black Canyon) | 10-18, BWO 18-20 |
| Oct | BWO, mahogany dun, midges | October caddis, streamers (Black Canyon) | BWO 18-22, caddis 8-12 |
| Nov+ | Closed to fishing inside the park | - | |
Season opener (late May / early June)
The Yellowstone River opens on the Saturday of Memorial Day weekend. Hayden Valley can be cold and blustery at opening - snow is not unusual in late May at this elevation. Caddis and BWO are typically the first productive hatches. The Black Canyon water below Tower Fall can fish well from opening day, particularly on warmer afternoons.
- Caddis - 14-16. Elk hair caddis and the caddis assortment.
- BWO - 16-20. Parachute BWO and Barr's Baetis emerger on overcast days.
- Stonefly nymphs 6-10 from nymphs along the bottom in faster water.
June
One of the best months on both sections. PMDs begin in the second week of June in Hayden Valley - the wide, open meadow river makes sight-fishing to rising cutthroat possible on calm mornings. Golden stones appear in the Black Canyon's faster water. Callibaetis become important on the slow flat sections near the lake outlet. The Black Canyon in June is uncrowded and fishing well.
- PMD - 16-18. Pale Morning Dun mornings. A pheasant tail nymph as a dropper.
- Golden stone - 8-10 in the Black Canyon riffles and pocket water.
- Callibaetis - 14-16 on the slow flat sections near the lake outlet. Parachute or sparkle dun style.
- Evening caddis. Elk hair.
July
Outstanding dry-fly fishing on both sections. PMDs continue through mid-month in Hayden Valley. Callibaetis are important on the flat outlet water. Tricos begin on the slower sections. Hoppers start along the valley grass and sage. July is peak visitation in the park - Hayden Valley road pulls can be crowded. Fish early morning before the tourist traffic builds, or hike into the Black Canyon for solitude.
- PMD - 16-18. Pale Morning Dun mornings.
- Callibaetis - 14-16. Flat sections near the lake outlet through midday.
- Trico - 20-22. Early morning spinner falls on slow flat water.
- Early hoppers along grassy valley edges - hoppers and terrestrials.
- Evening caddis. Elk hair.
August
Terrestrial season. Hoppers along the valley grass, trico spinner falls on the flat Hayden Valley water in the morning, ants and beetles in the foam lines. Cutthroat in both sections are willing - this is not Silver Creek selectivity. A well-placed hopper near the bank will bring fish. Fish early in Hayden Valley; the road crowds thin by late August. The Black Canyon in August is excellent with almost no other anglers.
- Hoppers - 8-12. Meadow bank edges in Hayden Valley, canyon pockets in the Black Canyon. Shop hoppers and terrestrials.
- Trico - 20-22. Morning spinner falls on flat Hayden Valley water.
- Callibaetis - 14-16 on the outlet flat sections.
- Ants and beetles in foam lines.
- Evening caddis.
September
One of the best months in the park. Crowds drop sharply after Labor Day. Hoppers hold through mid-month. BWO return as nights cool. Mahogany duns add a second fall option. The Black Canyon in September - with fall colors, elk bugling in the canyon, and aggressive cutthroat - is one of the great fly fishing experiences in the Yellowstone ecosystem. Streamers pick up in the deeper Black Canyon pools toward the lower end.
- Hoppers and ants through mid-September.
- BWO - 18-20. Parachute BWO and Baetis emerger.
- Mahogany dun - 14-16 on overcast afternoons.
- Streamers in deeper Black Canyon pools at last light.
October
The season closes on the first Sunday in November, making October the last month on the park Yellowstone. Fall colors peak in the canyon. BWO and mahogany duns on gray afternoons. The Black Canyon is at its best and virtually empty. October caddis on warmer afternoons. Handle any brown trout near the lower Black Canyon carefully during the spawn.
- BWO and mahogany dun, 16-22. Best on cloudy, calm afternoons.
- October caddis - 8-12 on warmer days.
- Midges - 18-22 in the slow Hayden Valley pools.
- Streamers in the lower Black Canyon at last light.
A box for the park Yellowstone starts with PMDs, caddis, and BWO in the right sizes, adds callibaetis and trico patterns for the flat Hayden Valley water, and includes hoppers for August and September. The western dry and nymph assortment covers the core season - add callibaetis, tricos, hoppers, and mahogany duns and you're ready for both sections.