Fly Fishing Bitterroot River - Missoula

Overview

The lower Bitterroot flows through cottonwood-lined ranchland toward Missoula. Its wider channels combine gravel riffles, long runs and deeper pools for brown, rainbow and westslope cutthroat trout. Watch the seams and slower margins for feeding fish; nymphs cover deeper lanes, while dries and streamers suit different activity along the banks.

River Character and Fishing

The Missoula section flows through relatively flat terrain, creating a mix of fast riffles, deep runs, and classic freestone pools. The river bottom consists of cobble, gravel, and some sand, providing diverse habitat for trout and aquatic insects. The gradient is moderate to gentle, creating excellent holding water throughout the section. The banks are lined with cottonwoods, willows, and agricultural fields, providing essential cover and shade. The water clarity is typically good, though it can become slightly off-color during high flows or agricultural runoff. The wider channels reward careful attention to current seams, deeper runs and feeding fish along the edges.

This section supports excellent populations of wild brown trout, rainbow trout, and native westslope cutthroat trout, with fish typically ranging from 12 to 16 inches. The brown trout are particularly large and aggressive, often responding well to streamers, hoppers, and large attractor patterns. 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.

Hatch activity is good throughout the season, with a variety of mayflies, caddis, and stoneflies providing consistent dry fly opportunities. 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. Streamer fishing can be particularly productive, especially during higher flows or when targeting larger brown trout. Nymphing remains productive year-round, with various mayfly, caddis, and stonefly patterns being effective.

Spring runoff can raise and discolor the river, while lower seasonal water reveals gravel bars and more defined feeding lanes. Focus on slower margins and seams when the main current is strong, and switch between nymphs, dries and streamers as fish activity changes.