Madison River Hebgen Lake to Ennis Montana Hatch Chart

Southwest Montana. The Madison exits Yellowstone National Park at the west entrance and flows north through the Hebgen Lake reservoir system before resuming as a freestone river below Quake Lake. From there it runs roughly 50 miles through open ranch country and the Madison Valley to Ennis Lake, passing through the town of Ennis along the way.

This is big, fast, wade-able freestone water — riffle-heavy with long gravel runs, undercut banks, and productive side channels. Brown trout dominate the lower valley; rainbows are more common in the upper stretches below Quake Lake. Fish average 14–18 inches with trophy browns taken regularly, particularly in fall. The Madison is a blue-ribbon fishery and sees heavy float traffic in summer — wading pressure is highest near Ennis and at the main access points.

Check current Montana FWP regulations before you go. The Madison has specific gear restrictions and seasonal rules that vary by section. Hebgen Lake above the dam has its own season and regulations separate from the river.

Shop by type: dry flies, nymphs, Euro nymphs, hoppers and terrestrials, streamers.

Year at a glance

Month Primary hatches Also carry Typical sizes
Jan Midges BWO on mild days, stonefly nymphs 18-22
Feb Midges, BWO Small dark stonefly nymphs 16-22
Mar BWO, midges Stonefly nymphs, streamer for pre-spawn browns 16-22
Apr BWO, March Brown Early caddis, streamer 12-18
May Caddis, BWO Stonefly nymphs, runoff mid-month Caddis 14-16, BWO 16-20
Jun Salmonfly, golden stone, caddis PMD late month Stones 4-10, caddis 14-16
Jul PMD, caddis, yellow sally Tricos start, early hoppers 14-18
Aug Hoppers, tricos, caddis Ants, beetles, late PMD Hopper 8-12, trico 20-22
Sep Hoppers, BWO, mahogany dun Streamers for pre-spawn browns 10-18, BWO 18-20
Oct BWO, mahogany dun, October caddis Midges, streamers BWO 18-22, caddis 8-12
Nov BWO, midges Streamers for post-spawn browns 18-22
Dec Midges Small nymphs, streamers 18-22

January

Cold and slow. The Madison fishes year-round below Quake Lake. Midges are the main food source — fish are concentrated in deeper, slower runs and the warmer tailouts below riffles.

February

Olives begin on overcast afternoons. Midge adults cluster in back eddies. The lower valley near Ennis can fish well on calm winter days.

March

BWO pick up as days lengthen. No Skwala hatch to speak of on this stretch — the Madison runs cold longer than Rock Creek. Streamer fishing for pre-runoff browns can be strong in March, particularly in the lower valley.

April

Olives and March Browns add options. Caddis begin late in the month. Runoff typically starts building toward the end of April — fish the early part of the month before flows push.

  • BWO and March Brown, 12-18, on cloudy afternoons.
  • Early dark caddis at dusk.
  • Streamers in off-color water when flows rise.

May

Caddis hatches can be excellent in early May before runoff peaks. Mid-month the river typically blows out — often dirty well into June depending on snowpack. Fish the edges, the side channels, and any clear tributary mouths when the main river is pushing.

June

The salmonfly hatch is the event that defines the Madison's reputation. As flows drop and clear — usually mid-to-late June depending on the year — the salmonfly hatch moves upstream from the lower valley toward Quake Lake. Timing the leading edge of the hatch is everything. Golden stones follow behind and extend the big-bug fishing into early July. Book early; this stretch draws anglers from across the country during the salmonfly window.

  • Salmonfly - 4-8. A West Fork Salmonfly or large Stimulator hard against undercut banks and woody debris. Fish the leading edge upstream of where adults are thick.
  • Golden stone - 6-10. Overlaps and follows the salmonfly. A stone nymph dropper 18 inches below a dry covers both stages.
  • Evening caddis - 14-16. Elk hair throughout the month.
  • Late June: PMD begins in riffles, 16-18.

July

Outstanding summer dry-fly fishing. PMDs in the morning, caddis in the evening, hoppers starting along the valley grass. The river sees its highest float traffic — wade-anglers should target early morning or evening, and focus on the sections away from the main launch sites. Browns are aggressive and feeding confidently.

August

Hopper season on one of the best hopper rivers in Montana. The wide valley, long grass banks, and big brown trout make August a destination month. Trico spinner falls in the morning on flatter sections near Ennis. Fish early — afternoon winds can pick up in the valley and make casting difficult.

  • Hoppers - 8-12. The workhorse pattern. A hopper-dropper with a small nymph is the standard rig. Shop hoppers and terrestrials.
  • Trico - 20-22. Early morning spinner falls on flat water near Ennis.
  • Ants and beetles in foam lines and along grassy banks.
  • Late PMD on cool mornings.
  • Evening caddis.

September

One of the great months on the Madison. Hoppers hold through mid-September. Mahogany duns and olives arrive in the afternoon. Brown trout begin staging ahead of the spawn — the largest fish of the year move into shallower feeding lanes and respond aggressively to both dries and streamers. Crowds drop sharply after Labor Day.

  • Hoppers and ants through mid-September.
  • Mahogany dun - 14-16 on gray afternoons.
  • BWO - parachute BWO and Baetis emerger, 18-20.
  • Streamers at first and last light for staging browns.

October

Fall colors in the valley and aggressive pre-spawn brown trout. October caddis in the afternoons, olives and mahogany duns on cloudy days. Streamer fishing through the deeper slots and undercuts can produce the largest fish of the year. Handle spawning fish carefully and avoid walking on active redds.

  • October caddis - 8-12, large orange dry.
  • Mahogany dun and BWO on overcast days.
  • Midges in slow water.
  • Streamers — olive, black, and brown through deeper holding water.

November

Spawning winds down. Cold mornings and short days. BWO and midges in the warmest part of the afternoon. Post-spawn browns hold in deeper runs and respond to streamers.

  • BWO and midges, 18-22.
  • Streamers — swing through slower, deeper water.
  • Small nymphs through holding runs.

December

Midge and nymph program. Low, clear water and selective fish. Fine tippet and a careful approach on wade water near Ennis.

A western dry and nymph assortment covers the year. Add salmonfly patterns, hoppers, trico patterns, mahogany duns, and a full streamer box for the complete Madison experience.