Green River Wyoming Hatch Chart

Western Wyoming, from the headwaters in the Wind River Range south through Sublette County to Fontenelle Reservoir and beyond. The Wyoming Green River is a large, freestone river flowing through open sagebrush valleys and occasional canyon stretches - a very different character from the tailwater sections downstream in Utah. The upper Wyoming Green is primarily a cutthroat and brown trout fishery with a short but intense season dictated by snowmelt, runoff, and the high-elevation summer window.

Check current Wyoming Game and Fish Department regulations before you go. The Green River in Wyoming has special regulations that vary by section and water body. Verify current rules, license requirements, and any tribal land considerations before fishing.

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

The river

The Green River rises on the western slope of the Wind River Range near Kendall and flows south through the broad Green River Basin - one of the most sweeping high-desert valley systems in the American West. The upper river above Warren Bridge is the most prized trout water, flowing through meadows and willow flats with a strong population of Snake River fine-spotted cutthroat and brown trout. The river is wide, braided in places, and wades well in late summer when flows drop from runoff peaks.

The season on the Wyoming Green is compressed compared to lower-elevation rivers. Runoff from the Wind River Range typically clears by late June or early July, and the prime fishing window runs from July through October. The short season concentrates excellent hatches - particularly hoppers, caddis, and PMDs - into a 12-16 week window. Plan accordingly and do not arrive expecting prime conditions before mid-July in most years.

Access is via Wyoming Highway 191 and forest roads in the upper drainage. The stretch from Warren Bridge downstream through the BLM corridor offers significant wade and float access. Respect private land boundaries - much of the valley floor is privately owned and wade access may be limited to the river corridor.

Year at a glance

Month Primary hatches Also carry Typical sizes
Jan Midges Small nymphs 20-26
Feb Midges Small nymphs 20-26
Mar Midges, BWO Small nymphs 18-24
Apr BWO, midges Early caddis 16-22
May Runoff - nymphs and streamers Stonefly nymphs varies
Jun Runoff clearing - salmonfly, golden stone Caddis, stonefly nymphs Stones 4-10
Jul Caddis, PMD, golden stone Hoppers start, yellow sally PMD 16-18, caddis 14-16
Aug Hoppers, caddis, PMD Ants, beetles, trico Hopper 8-12, caddis 14-16
Sep Hoppers, BWO, caddis Mahogany dun, ants BWO 16-20, hopper 8-12
Oct BWO, midges October caddis, streamers BWO 16-20, midge 20-24
Nov Midges, BWO Small nymphs 18-24
Dec Midges Small nymphs 20-26

January - April

The upper Wyoming Green is largely inaccessible and unfishable January through April due to snow, ice, and extreme cold in the high basin. The river holds fish year-round but access roads are often impassable and conditions are severe. Midges and BWO provide limited dry-fly opportunities on mild days in March and April for the angler willing to make the effort - but these months are not worth planning a dedicated trip around. Wait for runoff to clear in late June or July for the prime season.

  • Midges - 20-26. Small nymphs subsurface on accessible lower sections.
  • BWO - 18-22 on overcast afternoons in April. Parachute BWO.

May - early June (runoff)

Snowmelt from the Wind River Range pushes the Green into full runoff from May through mid-June in most years - flows can be dangerously high and visibility near zero. This is not a fishable window for most visiting anglers. Nymphs and streamers on the lower, more protected sections can produce fish for locals who know the water, but plan your trip to arrive after runoff clears.

  • Stonefly nymphs - 4-10 in the slower margins if visibility allows. See nymphs.
  • Streamers on the lower sections for aggressive pre-runoff browns. Streamers.

Late June

The river begins clearing from runoff in late June - timing varies year to year depending on snowpack and spring temperatures. When flows drop and clarity returns the salmonfly hatch can be extraordinary on the upper Green. Golden stones follow close behind. This is one of the most underrated salmonfly hatches in Wyoming - the river sees far less pressure than nearby fisheries and fish that have seen few flies respond aggressively to big dries during the hatch window. Check flow data on the USGS gauge at Warren Bridge before making the drive.

  • Salmonfly - 4-8. West Fork Salmonfly hard against the banks and undercut willows.
  • Golden stone - 6-10. Drop a stone nymph below a golden stone dry.
  • Caddis - 14-16 in the evenings as the river clears.

July

The prime season opens in July. Flows stabilize, the river clears, and the full hatch sequence gets underway. PMDs begin on the flatter meadow sections and caddis dominate the evening fishing. Yellow sallies appear in the riffles. Hoppers start along the willow and sage banks by mid-month. July is the best month to experience the full range of the Wyoming Green's hatch activity before hopper season takes over completely.

August

Hopper season peaks in August and the Wyoming Green is one of the finest hopper rivers in the Rocky Mountain West. The combination of sage flats, willow banks, and large cutthroat and brown trout makes for exceptional terrestrial fishing. Fish hoppers tight to the banks with confidence - the fish are there and they are looking up. Caddis evenings remain strong. PMDs continue on the upper meadow sections in the morning. Ants and beetles fill the midday window. August is the best single month on the Wyoming Green.

  • Hoppers - 8-12. Hoppers and terrestrials along the sage and willow banks. Hopper-dropper with a small nymph dropper.
  • Caddis - 14-16 evenings. Elk hair.
  • PMD - 16-18 mornings on the upper meadow sections. Pale Morning Dun.
  • Ants and beetles midday. Hoppers and terrestrials.

September

September rivals August as the best month on the Wyoming Green. Hoppers continue through mid-month. BWO return strongly with the cooling temperatures - the fall olive hatches on the big meadow water are outstanding. Mahogany duns add an afternoon option. Fewer anglers than August and fish in prime condition before the cold sets in. The upper river corridor in September is one of the most beautiful and productive stretches of freestone trout water in Wyoming.

  • Hoppers through mid-September. Hoppers and terrestrials.
  • BWO - 16-20. Parachute BWO and CDC Baetis emerger on overcast afternoons.
  • Mahogany dun - 14-16 on overcast afternoons.
  • Caddis evenings through mid-September. Elk hair.

October

BWO and midges dominate in October as the season winds toward close. October caddis add a large dry-fly option on warmer afternoons. Brown trout begin pre-spawn movement and streamers produce the largest fish of the year. The upper river can see early snow in October - check conditions and access road status before making the trip. A mild October day on the Wyoming Green with BWO hatching and browns moving is a special experience.

  • BWO - 16-20. The dominant hatch. Parachute BWO.
  • October caddis - 8-10 on warmer afternoons.
  • Midges - 20-24. Red zebra midge subsurface.
  • Streamers for pre-spawn browns - streamers in the deeper runs and undercut banks.

November - December

The upper Wyoming Green closes down for the season in November as snow and cold return to the high basin. Access roads may be impassable. The lower sections near the reservoir remain fishable on mild days with a midge and BWO program, but these months are not worth a dedicated trip to the upper river. The Wyoming Green is a summer and fall fishery - plan your visit for July through October.

  • Midges - 20-26 on accessible lower sections. Red zebra midge.
  • BWO - 18-20 on mild overcast days. Parachute BWO.

A western dry and nymph assortment covers the core season. Add a salmonfly pattern for late June, and a full hopper box for August and September. The Wyoming Green rewards anglers who time their visit correctly - arrive after runoff clears and before the first October snow, and you will find one of the most productive and least crowded big freestone rivers in the Rocky Mountain West.