Bitterroot River
Bitterroot Valley · Hamilton to Missoula
W Montana, USA
Open live forecast →Target species: Brown, Rainbow, Cutthroat, and Bull Trout.
Stream gauge: 12344000. Flow and water temperature update on every refresh.
Weekly AI Outlook as of 06/05/26
The Bitterroot is running 2,390 cfs at 48.4°F — perfect flows but water temps are still just below key emergence thresholds. Golden Stones are showing up in spots per Grizzly Hackle, though we need another degree or two for consistent dry fly action. PMDs are starting to appear but won't be reliable until water hits 52°F. Focus deep nymphing with Jig PTs and TNT PMDs in soft water, plus aggressive streamer fishing with articulated patterns while trout are still feeding heavy before the surface activity picks up.
- Flow: 2,390 cfs — right in the sweet spot for wade/float fishing with clear water and excellent access to prime holding lies
- Hatches: Golden Stones emerging sporadically, PMDs starting but inconsistent. Water needs 2-3°F warming for reliable dry fly fishing
- Water Temp: 48.4°F — just below key thresholds. Caddis at 50°F, consistent PMDs at 52°F, reliable Goldens at 55°F
- Best Window: All day nymphing and streamers. Midday warmup (11am-2pm) your best shot for surface activity if temps climb
Generated weekly from live USGS gauge readings, weather forecasts, and recent fly shop reports. Updates Friday mornings.
About this Water
- Freestone
- Best months: May–Oct, peak June & Sept–Oct
The Bitterroot flows north through one of Montana's most scenic valleys, flanked by the dramatic Bitterroot Range to the west and the Sapphire Mountains to the east. It offers excellent dry fly fishing for brown and rainbow trout through long summer and fall seasons, with productive riffles, runs, and undercut banks throughout its length. The Bitterroot's warm summers can stress fish in low-water years — early morning fishing is key from mid-July onward.
The Bitterroot's October streamer fishing for large brown trout during the fall spawning migration is one of the region's most productive — and overlooked — late-season opportunities.
January Outlook
January on the Bitterroot is quiet but possible in the canyon sections below Darby, which stay open most winters. Midge fishing in the deep canyon pools for dedicated anglers who can handle the cold.
Productive Patterns
- Zebra Midge
- RS2
- WD-40
- Soft Hackle
Tips
The lower canyon near Hamilton fishes best in January. Target slow inside bends and pools with a two-midge indicator rig. Valley sections may freeze — stick to the canyon.
Water Notes
700–1,200 cfs. Valley sections freeze; canyon stays open. Water 34–40°F.
February Outlook
February sees the first Skwala nymphs becoming active in the lower canyon. Midging continues to produce fish. On the warmest afternoons (50°F+), a brief Skwala dry fly moment is possible.
Productive Patterns
- Zebra Midge
- Hare's Ear
- Brown Rubber Leg
- RS2
Tips
Check the lower canyon near Florence or Stevensville on the warmest February days. Fish stonefly nymphs through the riffle-to-run transitions. The season feels close on a warm February afternoon.
Water Notes
800–1,500 cfs. Stable canyon flows. Water 38–46°F. Watch for first Skwala crawlers on exposed rocks.
March Outlook
Skwala stoneflies emerge in the lower Bitterroot canyon in March. This is a top-5 early season experience in Montana — large wild brown trout eating big dries in late winter conditions.
Productive Patterns
- Skwala Stone #8
- Brown Rubber Leg
- Sparkle Dun #18
- Hare's Ear
Tips
The canyon stretch below Darby is prime. Mornings are for nymphs; afternoons (45–55°F air temps) produce the Skwala dry fly action. Fish banks and shallow runs where stoneflies crawl. Call Hamilton fly shops for current hatch status.
Water Notes
900–2,000 cfs in early March, building toward runoff. Fish early in the month — runoff arrives by mid-to-late March.
April Outlook
Skwala stonefly action in the canyon sections before runoff peaks. Lower valley clears earlier than the upper river.
Productive Patterns
- Skwala Stone
- Hare's Ear
- Sparkle Dun #18
- Brown Rubber Leg
Tips
The canyon below Darby typically runs lower and clears faster. Target this stretch in early April. Skwala dries work on warmest afternoons.
Water Notes
Flows rise from 1,000 to 4,000+ cfs through April. Check the Victor gauge — below 2,500 cfs generally fish well.
May Outlook
Runoff subsides. PMDs and Caddis begin appearing. Hamilton area sections often clear first.
Productive Patterns
- PMD Sparkle Dun
- Elk Hair Caddis
- Gold Ribbed Hare's Ear
- Stimulator
Tips
Watch the gauge and plan when flows drop below 2,000 cfs. Section below Stevensville clears faster than above Hamilton.
Water Notes
Flows falling from peak, targeting 1,200–2,500 cfs. Clears relatively quickly for a valley river.
June Outlook
Best conditions of the year. Golden Stones, PMDs, and Caddis overlap for consistent dry fly fishing.
Productive Patterns
- Golden Stone
- PMD
- Elk Hair Caddis
- Stimulator #10
Tips
Float from Darby to Stevensville for best coverage. Long riffles and runs provide consistent holding water. Evening caddis is a Bitterroot highlight.
Water Notes
1,000–2,500 cfs ideally. Clear and cold 52–60°F.
July Outlook
Hopper-dropper season on the meadow sections. Ranch lands create textbook terrestrial habitat with cut banks.
Productive Patterns
- Chubby Chernobyl
- Dave's Hopper
- PMD Cripple
- Soft Hackle Caddis
Tips
Target undercut banks along ranch lands below Stevensville. Fish hold in shade of cut banks and eat hoppers confidently. Float fishing covers most productive water.
Water Notes
700–1,500 cfs. Water 62–68°F — warm but manageable. Fish morning and evening on hottest days.
August Outlook
Good hopper fishing but water temps require attention. Fish early morning and target shaded sections during midday heat.
Productive Patterns
- Dave's Hopper
- Parachute Ant
- Elk Hair Caddis
- Nymph Dropper
Tips
Water temps can approach stress levels — fish early and late. Darby to Conner section runs cooler than lower valley.
Water Notes
500–900 cfs. Water 65–70°F midday. Upper sections 4–5°F cooler. Monitor temps.
September Outlook
The Bitterroot's finest month. Cooling temps, falling flows, reliable BWO hatches, and spectacular autumn foliage.
Productive Patterns
- Blue Winged Olive
- Mahogany Dun
- Hopper
- Streamer
Tips
September BWO hatch is excellent — fish flat water between Stevensville and Hamilton on overcast afternoons. Streamers along cut banks in the morning.
Water Notes
400–800 cfs. Clear and cool 52–60°F. Excellent wading.
October Outlook
Brown trout streamer season and last of the fall dry fly hatches. Fish in superb condition before winter.
Productive Patterns
- Articulated Streamer
- Blue Winged Olive
- Egg
- Copper John
Tips
Work canyon sections below Darby with streamers in the morning. Target rising fish during afternoon BWO window. Respect active spawning redds.
Water Notes
350–600 cfs. Crystal clear. Sight fishing to staging fish is possible.
November Outlook
The Bitterroot in November transitions from fall fishing to early winter. Brown trout spawning concludes. Midging in the canyon sections produces fish on mild days. The fall foliage is long gone but the river is beautiful in its winter character.
Productive Patterns
- Zebra Midge
- Juju Baetis
- RS2
- Pheasant Tail #20
Tips
Focus the canyon below Darby for November access. Fish noon–2pm when temps peak. Leave spawning areas alone. The season is quiet but the river still holds many willing fish.
Water Notes
500–900 cfs. Cold and stable. Canyon 38–46°F. Valley sections approaching freezing nights.
December Outlook
December on the Bitterroot is specialized. Canyon sections fish on mild days for those who know the water. Midge hatches in the deep pools noon–2pm.
Productive Patterns
- Zebra Midge
- RS2
- Mercury Midge
- WD-40
Tips
The canyon stretch near Victor and Stevensville can fish on mild December days. Indicator nymph rig with small midges. Be prepared for cold and variable conditions.
Water Notes
500–800 cfs. Cold — 34–40°F. Canyon pools stay fishable on milder days.
Hatch Calendar
| Insect | Peak | Active | Size | Productive Patterns |
|---|---|---|---|---|
| Skwala Stonefly Skwala americana |
Mar, Apr | Mar, Apr | #8–10 |
|
| Blue Winged Olive Baetis tricaudatus |
Apr, Oct | Mar, Apr, May, Sep, Oct, Nov | #18–22 |
|
| Caddis (Mother's Day Grannom) Brachycentrus occidentalis |
May | Apr, May | #14–16 |
|
| Salmonfly Pteronarcys californica |
Jun | May, Jun | #4–6 |
|
| Golden Stonefly Hesperoperla pacifica |
Jun, Jul | Jun, Jul | #8–12 |
|
| Green Drake Drunella grandis / D. doddsi |
Jun | Jun, Jul | #10–12 |
|
| Pale Morning Dun Ephemerella inermis |
Jul, Aug | Jun, Jul, Aug, Sep | #16–18 |
|
| Caddis Hydropsyche / Brachycentrus spp. |
Jul, Aug | Jun, Jul, Aug, Sep | #14–18 |
|
| Trico Tricorythodes spp. |
Aug | Aug, Sep | #20–24 |
|
| Hoppers Acrididae / Tettigoniidae |
Aug | Jul, Aug, Sep | #8–12 |
|
Access & Approach
Hamilton, MT is the hub town. Numerous Montana FWP public fishing accesses throughout the valley. Both float and wade options available — drift boats preferred for the lower river. Local shops in Hamilton and Missoula are excellent resources.
Nearby Fly Shops
- Missoulian Angler
- Grizzly Hackle
Regulations & License
Fishing in Montana requires a current license. Always verify season dates, bag limits, and any special-regulation waters before you fish.
Montana fishing regulations & license →
Nearby Waters
Closest Waters
More in This Region
About Current
Bitterroot River conditions on Current combine real-time flow data (USGS, WSC, CDEC, CEHQ), weather, tide predictions, hatch probabilities calibrated to this specific water, and recent fly shop reports from the area.
Bitterroot River is one of 245 hand-curated waters in Current. The app and web forecast also generate AI outlooks for any unlisted river, lake, or saltwater flat anywhere in the world — drop a pin or paste a name and Current produces a fresh seasonal outlook with weather, flow context, and recommended techniques.
Open the live forecast for today's numbers and the 7-day outlook, or download the iOS app to carry it with you on the water.