Western Montana Fly Fishing Report
Regional River Conditions Overview
Western Montana rivers are still elevated across the Bitterroot, Blackfoot, Clark Fork, Rock Creek, and West Fork of the Bitterroot, but several key gauges are dropping and clearing compared with the heavier runoff push earlier in May. The Bitterroot is the best bet this week because it offers the best mix of fishable flow, access, edge structure, side channels, and current breaks. The Blackfoot, Clark Fork, Rock Creek, and West Fork remain technical, but they are becoming more reasonable as flows settle. Detailed river-by-river reports appear lower on the page.
Bitterroot River
Conditions
Water temp: 50–58°F. The Bitterroot is still carrying strong spring volume, but it has improved and is the best overall option in the region. Bell Crossing is around 3,510 CFS, the upper river near Darby is roughly in the low 2,000s, and the lower river near Missoula is still elevated but far more manageable than last week’s bigger water.
Where to Fish
- Side channels with walking-speed current
- Soft inside bends with depth
- Protected bank seams below current breaks
- Slow tailouts and edges near structure
- Calm flats and back-eddies during visible hatch activity
- Avoid fast outside bends and heavy mid-river current
How to Fish It
- Start with nymphs or a streamer before committing to dries
- Use short, controlled drifts close to the bank
- Fish worms, stonefly nymphs, dark mayfly nymphs, and caddis larva through soft edges
- Use streamers tight to banks when visibility allows
- Switch to dries only when fish are visibly rising in softer water
- Watch for wood and debris if floating; runoff has moved things around
Top Patterns
- Stonefly nymph, size 6–10
- Worm pattern, red or wine
- Dark mayfly nymph, size 12–16
- Caddis larva or pupa, size 12–16
- BWO emerger, size 16–18
- Caddis dry, size 12–16
- Olive or black streamer, size 4–6
Blackfoot River
Conditions
Water temp: 49–53°F. The Blackfoot near Bonner is around 3,110 CFS, which is a big improvement from the heavier push but still a strong, pushy river. This is mostly a subsurface and streamer game with limited dry-fly consistency.
Where to Fish
- Lower-river inside corners
- Soft shelves below heavy current
- Back-eddies with depth
- Banks and boulder edges with real current breaks
- Slower tailouts below structure
- Skip fast pocket water that cannot be controlled
How to Fish It
- Use heavy nymph rigs and short drifts
- Fish close to the bank
- Run stonefly nymphs, worms, and heavy attractor nymphs
- Streamer fish slower edges and buckets below structure
- Keep wading conservative even though the river is dropping
Top Patterns
- Stonefly nymph, size 6–10
- Worm pattern, red or wine
- Heavy attractor nymph
- Dark mayfly nymph, size 12–16
- Caddis larva, size 12–16
- Black or olive streamer, size 4–6
Clark Fork River
Conditions
Water temp: 50–55°F. The Clark Fork is dropping and becoming more realistic in the upper and middle reaches, with the river above Missoula around 4,670 CFS and below Missoula around 8,420 CFS. It is still big water, especially below Missoula, but the upper river is starting to fish better as clarity improves.
Where to Fish
- Soft edges above Missoula
- Protected bank seams below structure
- Backwater areas and side channels
- Slower shelves with depth
- Foam lines along calm inside banks
- Avoid the lower-river main push unless floating with experience
How to Fish It
- Nymph deep in softer edge water
- Fish streamers tight to banks and current breaks
- Use dry-dropper only when fish are feeding in calm edge water
- Avoid broad, fast current where drift control is impossible
- Look for trout tucked where current speed drops sharply
Top Patterns
- Stonefly nymph
- Worm pattern
- Sowbug-style pattern
- Dark mayfly nymph
- Caddis larva or pupa
- BWO emerger
- Olive or black streamer
Rock Creek
Conditions
Water temp: 47–52°F. Rock Creek near Clinton is around 1,090 CFS and dropping, which is a major improvement from the higher runoff push. It is still technical, but clarity and access are improving. Wading is more reasonable than last week, but it is not casual yet.
Where to Fish
- Lower-creek soft margins
- Inside bends with slower current
- Boulder edges with refuge water
- Back-eddies and bank pockets
- Protected tailouts during evening bug activity
- Avoid unnecessary crossings and fast mid-channel lanes
How to Fish It
- Nymph short, especially in pocket-water edges
- Use streamers in softer bank water
- Fish dries only when trout rise in protected water
- Watch for caddis, BWOs, March Browns, and occasional drake activity
- Fish fewer lanes and fish them better
Top Patterns
- Stonefly nymph
- Worm pattern
- BWO emerger, size 16–18
- March Brown adult, size 12–14
- Caddis larva or dry, size 12–16
- Large mayfly nymph, size 10–12
- Black or olive streamer, size 4–6
West Fork of the Bitterroot
Conditions
Water temp: 45–51°F. The West Fork near Conner is around 912 CFS, which is still high but easing. It may be cleaner than the freestone systems, but anglers should still treat it like high water and focus on soft structure.
Where to Fish
- Soft banks below Painted Rocks through Conner
- Protected tailouts with moderate current
- Inside seams with slower flow
- Edges below wood, boulders, and structure
- Calm seams during afternoon BWO and caddis activity
- Avoid fast riffles and pushy mid-channel water
How to Fish It
- Nymph first and stay near the bottom
- Use heavier flies than normal for the West Fork
- Fish short, accurate drifts through soft water
- Watch for afternoon caddis and BWO activity in protected seams
- Use 5X or 6X only when fish are clearly up and eating dries
- Keep wading conservative
Top Patterns
- Stonefly nymph
- Dark mayfly nymph
- Caddis larva or pupa
- BWO emerger, size 16–18
- Soft hackle, size 12–16
- Caddis dry, size 12–16
- Small olive streamer
Planning Note
Warm weather early this week may bump flows again, especially after sunny afternoons and the Memorial Day warm-up. Fish late morning through mid-afternoon, but watch the hydrographs and be ready to adjust if the rivers rise overnight.
If you want the best odds, start with the Bitterroot and fish the softest edges you can find. If the water looks too fast to control a drift, it is too fast. Tiny miracle, the river is still in charge.
River Flow Snapshot – May 24, 2026
Current gauge values are based on the latest available USGS and river-flow readings reviewed for this weekly report.
| River | Section | Gauge | Flow (CFS) | Trend / Status |
|---|---|---|---|---|
| Bitterroot | Upper | Near Darby (12344000) | 2,130 | High / Easing |
| Bitterroot | Middle | Bell Crossing nr Victor (12350250) | 3,510 | Elevated / Fishable Edges |
| Bitterroot | Lower | Near Missoula (12352500) | 3,960 | Elevated / Improving |
| Blackfoot | Lower | Near Bonner (12340000) | 3,110 | Elevated / Pushy |
| Clark Fork | Upper | Above Missoula (12340500) | 4,670 | Elevated / Improving |
| Clark Fork | Lower | Below Missoula (12353000) | 8,420 | Big Water / Improving |
| Rock Creek | Lower | Near Clinton (12334510) | 1,090 | Elevated / Technical |
| West Fork Bitterroot | Lower | Near Conner (12342500) | 912 | High / Cleaner Option |
Flows are still elevated, but the region is improving. The best fishing water this week is soft edge water, side channels, back-eddies, and protected seams close to the bank.
Fly Box of the Week
Dry Flies
- BWO dun, size 16–18
- BWO emerger, size 16–18
- March Brown adult, size 12–14
- Caddis dry, size 12–16
- Foam stonefly dry, size 8–10
- Large mayfly dry, size 10–12
Nymphs
- Stonefly nymph, size 6–10
- Worm pattern, red or wine
- Dark mayfly nymph, size 12–16
- Caddis larva or pupa, size 12–16
- Heavy attractor nymph
- BWO nymph, size 16–18
Streamers
- Olive streamer, size 4–6
- Black streamer, size 4–6
- Sculpin-style streamer, size 4–6
Hatch and Fly Chart – Late May Runoff Edition
| Hatch / Insect | Activity | Best Time | Recommended Fly | Size |
|---|---|---|---|---|
| Blue-Winged Olive | Active in softer water and cloudy windows | Late morning to afternoon | Dun or emerger | 16–18 |
| March Brown | Still possible in protected seams | Noon – 3 p.m. | Adult, emerger, or soft hackle | 12–14 |
| Caddis | Active, best in calm edges and evening windows | Afternoon into evening | Dry, pupa, or larva | 12–16 |
| Stoneflies | Nymphs matter; larger dries are situational | Subsurface all day | Stonefly nymph or foam dry | 6–10 |
| Drakes / Larger Mayflies | Possible on select soft water, especially as clarity improves | Afternoon | Large mayfly nymph, emerger, or dry | 10–12 |
Bugs are around, but water type still controls the fishing. Hatch activity matters most where trout can actually hold: soft banks, side channels, inside seams, calm tailouts, and protected back-eddies.
Gear Picks of the Week
6-Weight Rod
Elevated flows, heavier nymph rigs, and streamers all favor a 6-weight this week. A 5-weight works for soft-water dries, but the 6-weight gives better control.
Split Shot + Larger Indicators
Depth and drift control still matter more than fly variety. Carry enough weight to get down quickly in short, controlled lanes.
Studded Boots + Wading Staff
Flows are improving but still elevated. Good traction and a wading staff keep this a fishing report instead of a medical bill with scenery.
Strategy and Expectations This Week
This is an improving runoff report, not a full green-light summer report. Success this week means finding the slowest useful water, getting flies down quickly, and switching to dries only when fish are actively feeding in protected water. The Bitterroot gives anglers the best odds, but even there, the productive water is tight to the edges and slower than most people want to fish.
A good day this week is steady action from carefully chosen soft water. A wasted day is forcing fast water because it looks good from the road. The trout continue to care very little about road appeal.
