Troutline

West Fork Bitterroot River

Montana·Western Montana·45.82° N, 114.21° W
Flow
156 CFS
West Fork Bitterroot River nr Conner
Water Temp
—
Condition
Below Normal
Weather
64°F
Partly Cloudy
near Conner

Insights

Wind
Wind 3 mph — calm
Easy casting and clean surface presentations.
Flow
Low flows at 156 CFS
Fish are spooky. Lighten tippet and lengthen leaders.

The West Fork is the tailwater half of the Bitterroot's two headwater forks. It drops out of Painted Rocks Reservoir and runs roughly fifteen miles of riffle-run-pocket water northeast to meet the East Fork near Conner, where the two combine to form the main Bitterroot. What sets it apart from the freestone rivers all around it is the dam: Painted Rocks releases stored water into the West Fork from about mid-July through late September, so while the rest of the drainage is dropping and warming into late summer, this reach holds cool, wadeable flows and keeps fishing. That single management fact is why the water below the dam grows bigger cutthroat, rainbows, and the occasional heavy brown than the small-stream water above the reservoir.

It fishes like a tailwater with a freestone accent — faster pocket water broken up by riffles, runs, and rock gardens rather than the flat spring-creek glides the word "tailwater" might suggest. Summer base flows sit around 200-400 CFS at the Conner gauge, genuinely pleasant water to wade or float in a raft or small drift boat, though the upper reach below the dam closes to floating July 1 through September 15, making it a wade fishery in peak summer. Because the reservoir release schedule — not basin snowmelt — drives late-summer flows, the reach stays clean and cold when the freestone forks fade; watch the release timing more than the snowpack once July arrives. Hatches run about two weeks behind the rest of Montana because the cold releases keep water temperatures down, so the salmonfly and golden stone window pushes into July here and the spruce moth carries into late summer after those events have wrapped elsewhere.

Above the reservoir the West Fork reverts to a genuine freestone small stream where native westslope cutthroat come readily to dry flies from spring into early fall. Access below the dam is straightforward and public: the West Fork Road parallels the river past a string of Forest Service accesses and campgrounds — Hannon Memorial, Trapper Creek Job Corps, Applebury, Rombo, Alta. Cell service drops within a few miles of turning up the road. Darby is the nearest services town and sits right by the forks' confluence; Hamilton is the valley's main shop town about 20-25 minutes north.

Species

  • Westslope Cutthroat Trout
    Primary · Jun-Sep · 8-16"

    The signature native — abundant and dry-fly eager, especially in the freestone water above the reservoir, with larger fish below the dam. Catch-and-release only.

  • Rainbow Trout
    Common · Jun-Oct · 10-18"

    Common below Painted Rocks Dam, with some fish to 18"+. Catch-and-release only during general season.

  • Brown Trout
    Present · Sep-Nov · 12-20"+

    Fewer than cutthroat and rainbow, concentrated in the lower tailwater toward the confluence. Best on streamers in fall. Harvest allowed (3/day).

  • Brook Trout
    Present · Jun-Sep · 6-12"

    In the small freestone water above the reservoir and the headwater tributaries.

  • Mountain Whitefish
    Common · Year-round · 8-16"

    Abundant native and a reliable nymphing target through the cold months.

Ideal wading flow200–400 CFS
Blow-out>1,000 CFS
Ideal water temp48–62°F

Summer (Jul-Aug) is prime — cold Painted Rocks releases, stonefly and spruce-moth hatches, and stable flows when other rivers fade. Fall (Sep-Oct) is strong for Hecuba, BWO, and pre-spawn browns on streamers. Spring (Mar-Apr Skwala) is a short pre-runoff dry window. Late-spring and early-summer runoff is the low point, and the reach only really blows out when snowmelt tops the spillway.

Sections

4 sections on this river

Trapper Creek Job Corps to Hannon Memorial FAS

FloatBrown Trout · Rainbow Trout

The lowest, widest, and warmest of the three West Fork reaches, transitioning toward the main-stem confluence near Conner. The most popular float below the dam and home to the river's largest fish.

Best for: Float fishing — streamers for brown trout in fall, hoppers and Hecuba in late summer, and BWOs in fall; also holds rainbow trout.

Applebury to Trapper Creek Job Corps

Wade & FloatCutthroat · Rainbow Trout

Continuing riffle-run-pool tailwater with freestone character increasing downstream as tributaries enter. Productive, less-technical dry-fly water with easy roadside access.

Best for: Wade or raft for cutthroat trout and rainbow trout on dries, dry-dropper, and nymphs.

Painted Rocks Dam to Applebury

WadeSalmon · Cutthroat · Rainbow Trout

The coldest, most tailwater-influenced water — fast pocket water, riffles, runs, and rock gardens directly below the dam, and the cleanest reach during runoff. This is the stretch that still fishes cool and clear in August when the dam is releasing.

Best for: Wade fishing for westslope cutthroat trout and rainbow trout on dries and dry-dropper; salmonfly and golden stone in July, spruce moth in late summer.

Above Painted Rocks Reservoir (Headwaters)

WadeCutthroat · Brook Trout · Rainbow Trout

A genuine freestone small stream above the reservoir around Alta — snowmelt-driven rather than tailwater, and distinct in character from the water below the dam.

Best for: Wade fishing small dries for eager native westslope cutthroat trout and brook trout in the backcountry.

Regulations

Current fishing rules and restrictions

Montana FWP Western Fishing District, West Fork Bitterroot downstream of Painted Rocks Dam. Cutthroat and rainbow are catch-and-release only; brown trout harvest is allowed. Floating is closed on the dam-to-Applebury reach in peak summer.

  • General season: third Saturday in May through November 30.
  • Cutthroat and rainbow trout: catch-and-release only during general season.
  • Brown trout: 3 daily and in possession (harvest allowed).
  • Extended season (Dec 1 - third Saturday in May): catch-and-release for all trout; artificial-lure / aquatic-insect / maggot bait restriction districtwide (no live fish as bait).
  • Floating closed July 1 - September 15 on the Painted Rocks Dam to Applebury reach; commercial floating also restricted on certain days June 1 - Sep 15.
  • Montana resident or nonresident fishing license required.

The peak-summer float closure makes the upper tailwater (dam to Applebury) a wade fishery July through mid-September. Regulations change annually — verify against the current MT FWP regulations before fishing.

Source: Montana Fish, Wildlife & Parks — Western Fishing District. Regulations change annually — verify before fishing.

Access & Logistics

Getting there, fly shops, and lodging

Getting There

Darby, MT

~1 hr 15 min from Missoula, then up the West Fork Road from Darby/Conner

Camping & Lodging

Bitterroot National Forest campgrounds along the West Fork Ranger District — Rombo, Alta, and Painted Rocks-area sites, plus primitive campsites at Applebury and along the upper road. Hannon Memorial FAS has 6 campsites and a boat launch. Motels and services in Darby and Conner.

The West Fork Road (paved, then Forest Service road) parallels the river past a string of public accesses. Cell service ends within a few miles of turning off US 93. Access is free with a Montana fishing license; FAS and Forest Service accesses are public.

Conditions data is live from public monitoring networks. Regulations change annually — always verify current rules with your state fish & wildlife agency before fishing.

More in Montana

View all 22 rivers

Western Montana

Bitterroot RiverMT

Western Montana's home water — 84 miles of cottonwood-bottomed valley fishing for wild rainbows, browns, and native westslope cutthroat. Famous for the March-April Skwala stonefly hatch and a long dry-fly season from spring through October.

Blackfoot RiverMT

The freestone river Norman Maclean made famous, rebuilt over 30 years of restoration into a genuinely wild fishery for westslope cutthroat, browns, and rainbows east of Missoula. No dam on the mainstem, a legendary June salmonfly hatch, and a boulder-strewn canyon corridor that fishes best from a drift boat.

Clark Fork RiverMT

Montana's longest river fishes like three waters in one — a skinny Superfund-recovery meadow stream up around Deer Lodge, a legitimate mid-size freestone through Missoula, and big float water down to St. Regis. Wild browns up top, 16-17" rainbows and cuttbows below town, and a marquee mid-September dry-fly window.

Rock CreekMT

Missoula's home freestone — about 50 miles of wadeable pocket water running from the Forks near Philipsburg down to the Clark Fork at Clinton. A Blue-Ribbon stream with five wild salmonid species and Montana's most famous June salmonfly hatch.

Other regions

Beaverhead RiverMT

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Big Hole RiverMT

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Bighorn RiverMT

The Yellowtail Dam tailwater — 13 miles of fly fishing gold from the Afterbay to Two Leggins. 3,000-5,000 trout per mile, year-round consistent flows, and the West's most reliable sow bug and PMD fishery.

East Gallatin RiverMT

Bozeman's spring-influenced backyard brown-trout stream — a small, weedy, serpentine meadow river that forms east of town and joins the West Gallatin near Manhattan. A separate drainage from the famous Gallatin canyon freestone: wade-only, technical, spring-creek-style fishing for wild browns, rainbows, and whitefish.

Flathead RiverMT

The big glacial-green valley river formed where the three forks meet near West Glacier, running through the Flathead Valley into Flathead Lake and continuing below Kerr Dam. A native westslope cutthroat dry-fly float up top, northern pike water down low.

Gallatin RiverMT

The Gallatin runs through Yellowstone NP and the Gallatin Canyon along Highway 191 — wadeable freestone water for rainbows, browns, cutthroat, and whitefish, with a strong salmon fly hatch in late June and excellent post-runoff dry-fly fishing into October.