Fly Fishing Bitterroot River - Darby

Overview

The upper Bitterroot near Darby flows north through meadows and conifer-lined banks below the Bitterroot Mountains. Cobble riffles, boulder pockets and deep pools hold brown, rainbow and westslope cutthroat trout, with mountain whitefish in the runs. Work the softer edges of fast water and seams beside cover, using short drifts where boulders break up the current.

River Character and Fishing

The Darby section flows through a mix of open meadows and conifer forests, creating a variety of water types including fast riffles, deep runs, classic freestone pools, and extensive pocketwater. The river bottom consists of cobble, boulders, and gravel, providing excellent habitat for both trout and aquatic insects. The gradient is moderate to steep in places, creating excellent holding water with fast seams and deep pools. The banks are lined with willows, aspens, and pines, providing essential cover and shade. The water clarity is typically excellent, with cold, highly oxygenated water that supports healthy trout populations. The river flows south to north, with the West Fork (downstream from Painted Rocks Dam) and East Fork (downstream from Star Falls) converging in the upper section.

This section supports healthy populations of wild brown trout, rainbow trout, and native westslope cutthroat trout, with fish typically ranging from 10 to 14 inches. The brown trout are particularly aggressive and opportunistic, often responding well to attractor patterns and terrestrials. Rainbow trout add variety and are known for their acrobatic fights. Native westslope cutthroat trout are present and add to the diversity of the fishery. Mountain whitefish are also abundant inhabit the gravel runs.

Spring brings blue-winged olive and Skwala opportunities before runoff reshapes the river. The section benefits from excellent mayfly and caddis hatches during summer, with active hatches including Blue-Winged Olives (BWOs), spring March Browns, and Skwalas offering dry-fly opportunities. Blue-winged Olives emerge in spring and fall, PMDs appear in mid-summer, and various caddis species provide excellent evening fishing. Terrestrial patterns become extremely effective from mid-summer through early fall, with hoppers, ants, and beetles producing excellent results when fished tight to the banks. Nymphing remains productive year-round, with various mayfly, caddis, and stonefly patterns being effective.

Spring runoff changes the river's pace and clarity, while lower seasonal water exposes more riffles and pocketwater. Work the softer edges of fast runs, seams beside boulders and the heads of pools; use nymphs when fish are feeding below the surface and dry flies when insects and rising trout are visible.

Access

Wally Crawford Fishing Access Site has parking and a concrete boat ramp. From US 93, turn east onto Old Darby Road 3.7 miles north of Darby and continue 0.25 mile to the site.