Rock Creek Montana Hatch Chart

Southwest Montana, southeast of Missoula. Rock Creek drains a long corridor of the Sapphire Mountains before joining the Clark Fork near Drummond. One of Montana's most celebrated wild trout streams — westslope cutthroat, brown trout, and rainbow trout in clear, freestone water.

The lower canyon is accessible by road. The upper drainage above the narrows is more remote and holds native cutthroat in smaller, faster water. Brown trout dominate the middle and lower river, with the largest fish moving into feeding lanes during the salmonfly and hopper seasons.

Rock Creek is heavily regulated to protect wild fish. Check current Montana FWP regulations before you go — sections have varying catch-and-release rules, gear restrictions, and seasonal closures. The river sees significant pressure during peak hatches; weekdays and early mornings fish better than weekend afternoons.

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, Skwala Midges, March Brown start 14-20, Skwala 8-12
Apr BWO, March Brown, Skwala Early caddis 12-18
May Caddis, stonefly nymphs BWO, runoff mid-month Caddis 14-16, stones 6-10
Jun Salmonfly, golden stone, caddis PMD late month Stones 4-10, caddis 14-16
Jul PMD, caddis, yellow sally Hoppers start, golden stone fading 14-18
Aug Hoppers, ants, caddis Late PMD, beetles, tricos Hopper 8-12, trico 20-22
Sep Hoppers, BWO, October caddis Mahogany dun, streamers 10-18, BWO 18-20
Oct October caddis, BWO, mahogany dun Midges, streamers Caddis 8-12, BWO 18-22
Nov BWO, midges Streamers for browns 18-22
Dec Midges Small nymphs, streamers 18-22

January

Cold and slow. The creek fishes best on the warmest part of the afternoon. Midges are the primary food source; fish hold in deeper, slower runs.

February

Olives start showing on overcast days, especially in the afternoon. Midge adults cluster in back eddies and can bring fish to the surface.

March

Rock Creek's early season opens with Skwala stoneflies — a warmwater indicator hatch that brings bigger brown trout to the surface before most rivers in the region have anything dry-flyable. BWO continue alongside.

  • Skwala - 8-12. Large olive-brown stone. Dead-drift a rubber-leg nymph along banks; switch to a Stimulator-style dry when you see adults on the water. See nymphs and dry flies.
  • BWO - 16-20. Dry and Barr's Baetis emerger on cloudy afternoons.

April

Skwala continue into early April. March Browns add a second dry-fly option on overcast days. Runoff typically begins in the second half of the month — fish the edges when flows push.

  • Skwala still effective early in the month.
  • March Brown and BWO on gray afternoons, 12-16.
  • Early dark caddis at dusk.

May

Caddis build toward the salmonfly season. Runoff peaks mid-month and can blow the creek out for one to three weeks depending on snowpack. Fish the first clear days after flows drop — caddis hatches can be dense.

June

The salmonfly hatch is Rock Creek's most famous event and draws anglers from across the country. The hatch typically moves upstream through the canyon over two to three weeks — starting in the lower river in early June and reaching the upper stretches by late month. Time the leading edge for the best dry-fly action. Golden stones follow close behind.

  • Salmonfly - 4-8. A West Fork Salmonfly or large Stimulator hard against the bank. Fish the water just ahead of where adults are landing.
  • Golden stone - 6-10. Overlaps and extends the big-bug window. A golden stone nymph as a dropper under a dry covers both stages.
  • Evening caddis throughout June — elk hair in 14-16.
  • Late June: PMD begins in riffles, 16-18.

July

Rock Creek hits its stride for dry-fly fishing. PMDs in the morning, caddis in the evening, and hoppers starting along the grassy banks. Brown trout are in full feeding mode. Pressure is high on weekends — go early or go deep into the upper canyon.

August

Hopper season in full effect. The big browns that hid through the heat of the day will slide out to eat a well-placed hopper in low light. Tricos appear in the morning on the slower lower stretches — technical fishing for rising fish. Fish early and late; midday heat pushes fish deep.

  • Hoppers, ants, beetles - hoppers and terrestrials. Hopper-dropper with a small nymph is the workhorse rig.
  • Trico - 20-22 on flat, slower water in morning spinner falls.
  • Evening caddis.
  • Late PMD on cool mornings.

September

One of the best months on Rock Creek. Hoppers stay good through early September. Mahogany duns and olives add a second dry-fly window in the afternoon. Crowds thin considerably after Labor Day. Brown trout begin staging for the fall spawn and respond well to streamers in low light.

  • Hoppers and ants through mid-September.
  • Mahogany dun - 14-16 in the afternoon, particularly on the lower river.
  • BWO - parachute BWO and the Baetis emerger, 18-20.
  • Early October caddis - large orange dry, 8-12.
  • Streamers at first and last light for pre-spawn browns.

October

Fall dry-fly fishing with October caddis and olives. Brown trout are in or near the spawn — handle carefully and avoid disturbing redds. Streamer fishing for non-spawning fish can be excellent in deeper pools.

  • October caddis afternoons and mahogany dun on cloudy days.
  • BWO and midges in slow water.
  • Streamers swung through deeper runs and pools.

November

Spawning activity winds down. Cold nights and short days. BWO and midges on the warmest part of the afternoon. Streamer fishing can be good for post-spawn browns recovering in holding water.

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

December

Midge program. Fish the warmest two hours of the afternoon. Low, clear water means fine tippet and a careful approach.

A western dry and nymph assortment covers the trout year. Add salmonfly patterns, hoppers, mahogany duns, and a streamer box for the full Rock Creek experience.