Yellowstone River Paradise Valley Hatch Chart

South-central Montana, from Gardiner to Livingston. The Yellowstone River exits Yellowstone National Park at Gardiner and immediately enters one of the most celebrated stretches of trout water in the American West - the Paradise Valley. For roughly 50 miles the river runs north through a wide mountain valley flanked by the Absaroka Range to the east and the Gallatin Range to the west, before reaching Livingston and the transition to the broader prairie valley below.

This is big freestone water - powerful, fast, and wade-able in places with care. Wild rainbow and brown trout throughout, with cutthroat more common in the upper reach near Gardiner. Fish average 14-18 inches with trophy fish - particularly large browns - present especially in the lower valley near Livingston. The Yellowstone is one of the longest free-flowing rivers in the lower 48, and the Paradise Valley section retains its wild, undammed character.

Check current Montana Fish, Wildlife and Parks regulations before you go. From the Yellowstone National Park boundary downstream to Pine Creek Bridge: catch-and-release for cutthroat trout. From the park boundary downstream to Springdale Bridge FAS: all smallmouth bass must be killed immediately, kept, and presented to FWP - report the catch within 24 hours at 406-577-7900. Other trout follow the printed Central District limit - confirm the current pamphlet for size and number. This river warms in midsummer and hoot-owl restrictions (2 p.m. to midnight) are common - if the water is near 73 degrees, fish early or wait. A Montana fishing license is required. Inside the park the river is a National Park Service fishery with its own season and permit.

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	Midge 18-22
Feb	Midges, BWO	Small dark stonefly nymphs	Midge 18-22, BWO 16-20
Mar	BWO, Skwala, midges	Streamers	BWO 16-20, Skwala 8-12
Apr	BWO, Skwala, March brown	Early caddis, streamers	BWO 14-18, Skwala 8-12
May	Caddis, BWO	Stonefly nymphs, runoff mid-month	Caddis 14-16, BWO 16-20
Jun	Salmonfly, golden stone, caddis	PMD late month	Stone 4-10, caddis 14-16
Jul	PMD, caddis, yellow sally	Hoppers start, tricos flat sections	PMD 16-18, hopper 8-12
Aug	Hoppers, caddis, trico	Ants, beetles, late PMD - monitor temps	Hopper 8-12, trico 20-22
Sep	Hoppers, BWO, mahogany dun	Streamers for pre-spawn browns	BWO 16-20, hopper 8-12
Oct	BWO, mahogany dun, October caddis	Midges, streamers	BWO 18-22, caddis 8-12
Nov	BWO, midges	Streamers for post-spawn browns	BWO 18-22, midge 18-22
Dec	Midges	Small nymphs, streamers	Midge 18-22

January - February

The Yellowstone fishes year-round through the valley. January midge activity can be excellent on calm, mild afternoons - fish concentrate in the inside bends and tailouts below riffles. The upper reach near Gardiner tends to fish better in winter due to geothermal influence from the park drainage. BWO increase on overcast February afternoons and the lower valley near Livingston can fish well on calm winter days. Midday is the window through both months.

Midges - 18-22. Two-fly rig through the slow tailouts and inside bends. The year-round subsurface anchor on the Yellowstone.
BWO - 16-20 on overcast February afternoons. Parachute and CDC emerger styles.
Small dark stonefly nymphs along the bottom in the faster runs.
Pheasant tail nymphs subsurface for Baetis through both months.

March - April

BWO pick up as days lengthen and the Skwala stonefly begins on the lower valley water when temperatures warm - the Yellowstone is one of the better Skwala rivers in Montana. Streamer fishing for pre-runoff browns is strong through March. April adds March brown and early caddis before runoff builds toward month's end - fish the first half of April before flows push. When the main river colors up, work the edges, side channels, and tributary mouths.

BWO - 16-20 on overcast afternoons through March and April. Parachute and CDC emerger styles.
Skwala - 8-12. Rubber-leg nymph along the banks, Stimulator-style dry on warm afternoons on the lower valley.
Streamers - olive and black, swung through the deeper runs. Best pre-runoff window of the year through March.
April: March brown 12-14, early caddis 14-16 at dusk.

May - June

Caddis hatches can be excellent in early May before runoff peaks. The Yellowstone typically blows out mid-month and often runs high through early June depending on Absaroka snowpack - fish the edges, side channels, and clear tributary mouths when the main river is pushing. The salmonfly hatch is the defining event of the Yellowstone's year. As flows drop and clear - usually mid-to-late June - the hatch moves upstream from the lower valley toward Gardiner. Golden stones follow and extend the big-bug fishing into early July. Book guides and lodges well in advance for the salmonfly window.

May: caddis - 14-16 early in the month. Stonefly nymphs 6-10 subsurface. BWO on overcast days when flows allow.
June: salmonfly - 4-8 hard against undercut banks, root wads, and cliff faces. Fish the leading edge upstream of where adults are thickest.
Golden stone - 6-10. Overlaps and follows the salmonfly. Stone nymph dropper below a large dry.
Evening caddis - 14-16 through June.
Late June: PMD - 16-18 in the riffles.

July - August

Outstanding summer dry-fly fishing on one of the best hopper rivers in Montana. PMDs in the morning, caddis evenings, hoppers building along the valley grass and sage through July. The river sees significant float traffic in July - wade anglers should target early morning and evening and focus on sections away from the main launch sites. Monitor water temperatures carefully through August - the Yellowstone can warm significantly in hot, dry years and FWP occasionally issues hoot owl restrictions. Fish early, fish efficiently, and release quickly.

July: PMD - 16-18 mornings. Yellow sally 14-16 in the faster riffles.
Caddis - 14-16 evenings through July and August.
Hoppers - 8-12 along the valley grass and sage from mid-July through August. Hopper-dropper with a small nymph.
Trico - 20-22 early morning on the flat sections near Livingston.
Ants and beetles in foam lines along the grassy banks midday.

September - October

One of the great months on the Yellowstone. 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 dries and streamers. Crowds drop sharply after Labor Day. October adds October caddis on warmer afternoons and extends the streamer season through the pre-spawn peak. Handle spawning fish carefully - avoid fishing to fish actively on redds.

Hoppers and ants through mid-September.
BWO - 16-20 on overcast afternoons through September and October. Parachute and CDC emerger styles.
Mahogany dun - 14-16 on gray afternoons through September and October.
October caddis - 8-12 on warmer October afternoons.
Streamers at first and last light through September and October for staging and pre-spawn browns.
Midges in the slow water and tailouts through October.

November - December

Spawning winds down and post-spawn browns hold in the deeper runs. BWO and midges in the warmest part of the afternoon through November. December returns to the midge and nymph program in low, clear water - the upper reach near Gardiner can fish surprisingly well on mild December days due to the geothermal influence from the park.

BWO - 18-22 on mild overcast November afternoons. Parachute and CDC emerger styles.
Midges - 18-22 throughout both months. Two-fly rig through the slower tailouts and inside bends.
Streamers - swung slowly through the deeper runs for post-spawn browns through November.
Small nymphs through the holding lies.

A western dry and nymph assortment covers the year. Add a salmonfly pattern for June, hoppers and terrestrials for the summer season, and a full streamer selection for the fall brown trout season - the complete Paradise Valley kit.