Madison River Yellowstone National Park Hatch Chart
Northwest Wyoming, inside Yellowstone National Park. The Madison forms at Madison Junction where the Firehole and Gibbon rivers meet, then flows west through a wide, geothermally influenced valley to the park boundary near West Yellowstone, Montana. This is a short river — roughly 14 miles — but one of the most storied stretches of trout water in the world.
Rainbows and brown trout dominate, with some brook trout in the upper reaches. Fish average 12–18 inches with larger browns present, particularly in fall. The Firehole influence keeps water temperatures warmer than most park streams, which affects both hatch timing and fish behavior — hatches can appear earlier in the season here than on other park drainages.
The Madison inside the park is fly-fishing only, catch-and-release, artificial lures only. The season 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. 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 | PMD 16-18, stones 8-10 |
| Jul | PMD, caddis, yellow sally | Early hoppers, tricos start | 14-18 |
| Aug | Hoppers, tricos, caddis | Ants, beetles, late PMD | Hopper 8-12, trico 20-22 |
| Sep | Hoppers, BWO, mahogany dun | Streamers for spawning browns | 10-18, BWO 18-20 |
| Oct | BWO, mahogany dun, midges | Streamers, October caddis | BWO 18-22, caddis 8-12 |
| Nov+ | Closed to fishing inside the park | — | |
Season opener (late May / early June)
The Madison opens on the Saturday of Memorial Day weekend. Early season conditions vary widely — some years see clear, fishable water immediately; others have elevated flows from snowmelt. The Firehole influence helps, keeping the upper Madison warmer and more stable than most opening-day rivers in the region.
- Caddis - 14-16. Early tan and gray caddis are often the first strong hatch. Elk hair caddis and the caddis assortment.
- BWO - 16-20. Reliable on overcast days. BWO dry and Barr's Baetis emerger.
- Stonefly nymphs 6-10 from nymphs — fish them along the bottom in faster runs.
June
One of the best months on the park Madison. PMDs begin in earnest in the second week of June and overlap with caddis and golden stones. The wide, open valley makes sight-fishing to rising fish possible on calm mornings and evenings. Bison are common along the banks — keep your distance.
- PMD - 16-18. Pale Morning Dun in the morning. A pheasant tail nymph underneath covers the emerger stage.
- Golden stone - 8-10. Present but not as dominant as on freestone rivers — still worth having a few in the box.
- Caddis - 14-16 in the evenings. Elk hair.
- Yellow sally - 14-16 in riffled sections.
July
The Madison valley in July is one of the great dry-fly experiences in American trout fishing. PMDs continue through mid-month. Tricos begin on the slower, flatter water near the west end of the valley. Hoppers start along the grassy edges. Crowds peak in July — arrive early and pick water away from the main pullouts.
- PMD mornings — Pale Morning Dun.
- Trico - 20-22. Morning spinner falls on flat water. Small, light patterns on fine tippet.
- Caddis evenings — elk hair.
- Early hoppers along grass banks — hoppers and terrestrials.
August
Terrestrial season. Hoppers along the banks, trico spinner falls in the morning, ants and beetles in the foam lines. The open meadow character of the Madison makes hopper fishing highly visual — watch for subtle sips near the bank and cast tight to the grass. Fish early; afternoon thunderstorms are common.
- Hoppers - 8-12. A hopper-dropper with a small nymph underneath covers both surface and subsurface feeders. Shop hoppers and terrestrials.
- Trico - 20-22. Early morning spinner falls, especially in the lower, slower valley sections.
- Ants and beetles in the foam lines and back eddies.
- Evening caddis.
September
Outstanding month. Hoppers hold through mid-September. Mahogany duns and olives take over in the afternoon. Brown trout begin moving and feeding aggressively ahead of the spawn — the largest fish of the year are caught in September on both dries and streamers. Crowds thin significantly after Labor Day.
- Hoppers and ants through mid-month.
- Mahogany dun - 14-16 on gray afternoons.
- BWO - parachute BWO and Baetis emerger, 18-20.
- Streamers at first and last light for staging brown trout.
October
The season closes on the first Sunday in November, making October the last month on the park Madison. Fall colors, few crowds, and aggressive pre-spawn browns make this a bucket-list window. BWO and mahogany duns on overcast days. Streamers in the deeper runs and undercuts.
- BWO and mahogany dun, 16-22. Best on cloudy, calm afternoons.
- Midges - 18-22 in the slow water.
- Streamers — olive, black, and brown in 3-5 inch patterns through holding water.
- Early October caddis - large orange dry, 8-12, on warmer days.
A western dry and nymph assortment covers the core season. Add hoppers, trico patterns, mahogany duns, and a streamer box for the full Madison experience.