FISHABLE
Winter flows stable, good midge activityBitterroot River
Current Hatch Activity
Winter midge activity best on sunny afternoons in slower water. BWOs sporadically hatching on warmer days.
FISHABLE
Midge dropper under dry (Griffith's Gnat + Zebra Midge #20-22)
Quick Reference
300-1,500 CFS ideal for wading. Below 300 can be skinny. Above 2,000 starts to get pushy.
45-65°F optimal. The Bitterroot warms quickly in summer—fish early.
Winter flows typically sit in the 300-500 CFS range. Spring runoff peaks mid-May to mid-June, often reaching 8,000-15,000 CFS.
Generally clear outside of runoff. First river in western Montana to clear after spring—usually fishable by late June.
What "Fishable" Means Here
Fishable means you can effectively present flies to actively feeding trout. On the Bitterroot, that typically requires flows under 2,000 CFS with reasonable visibility (2+ feet). During peak runoff, even locals head elsewhere.
Seasonal Patterns
spring
The Bitterroot wakes up early—often the first fishable water in western Montana by late February. March Browns and Skwala stoneflies bring fish to the surface before other rivers are even thawed. Runoff typically blows it out mid-May through mid-June.
summer
Post-runoff (late June) brings excellent dry fly fishing. PMDs, caddis, and Yellow Sallies dominate. Flows drop to 800-1,200 CFS. Watch water temps—afternoon fishing can be tough in July/August when temps exceed 65°F.
fall
September through October is prime time. Flows are low (400-700 CFS), fish are aggressive, and crowds thin out. October caddis and BWOs provide consistent surface action. Brown trout become more active as spawning approaches.
winter
Don't overlook winter fishing. Flows are low (300-500 CFS) and stable. Midges hatch on sunny afternoons. Focus on slower water and deeper runs. Fish are concentrated and catchable if you're willing to brave the cold.
Alternative Waters
Clark Fork River
When the Bitterroot is blown out, the Clark Fork often clears first below MissoulaRock Creek
Smaller freestone that clears quickly after runoff—good backup optionResources
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