Western Montana Fly Fishing Report
Current Restrictions and Closure Summary
Montana FWP currently lists no hoot-owl restrictions on the Bitterroot, Blackfoot, Clark Fork, Rock Creek, or West Fork Bitterroot.
- Blackfoot River: Closed to floating from Weigh Station Fishing Access Site downstream to the point where the river crosses beneath Interstate 90 because of railway bridge construction.
- Other core rivers: No current emergency fishing restrictions are listed for the Bitterroot, Clark Fork, Rock Creek, or West Fork.
- Check before fishing: Montana FWP updates its current restriction information throughout the day, so verify conditions before launching or recommending a section.
Regional River Conditions Overview
This week's flow picture is substantially better than it was at the end of August. The Bitterroot has gained water across the system, with the lower river back above 1,000 CFS. The Clark Fork has also received a meaningful bump, Rock Creek is carrying noticeably more water, and the Blackfoot remains near its historical early-September range.
Sunday and Monday are the weather days to watch. Cool temperatures, rain, and cloud cover should reduce bright-light pressure and give anglers a legitimate chance to fish through the middle of the day. Tuesday remains cool but brighter. Wednesday and Thursday warm into the upper 70s and around 80 degrees, then Friday brings another chance of clouds and showers.
The hatch menu is still more late-summer than full fall. Tricos remain important in slower morning water. Hoppers, ants, and beetles remain excellent prospecting patterns. Late PMD spinners and caddis are still around. BWOs are worth having during cool rain and cloud cover, but terrestrials, Tricos, PMDs, and caddis remain the more established program right now.
Bitterroot River
Conditions
The Bitterroot has improved considerably from last week. Latest readings are around 575 CFS near Darby, 513 CFS at Bell Crossing, and 1,010 CFS near Missoula. That is a meaningful improvement in holding water and gives the river substantially more structure than it had through much of August.
The river remains clear and presentation-sensitive, but trout should be less concentrated into tiny pieces of water. Sunday and Monday's clouds and rain could produce one of the best all-around Bitterroot windows we have seen in several weeks.
Where to Fish
- Riffle edges transitioning into deeper green water
- Foam lines and inside seams
- Tailouts and slicks during Trico activity
- Shaded banks and undercut grassy edges
- Deeper slots beside faster current
- Structure and banks during cloudy streamer conditions
How to Fish It
- Look for Trico spinners on slower morning water
- Use hoppers, ants, beetles, and small attractors to prospect banks and broken water
- Fish small Perdigons, Frenchies, Pheasant Tails, and caddis pupa under a terrestrial
- Use longer leaders and 5X–6X when fish are visibly rising in slick water
- Watch for PMD spinners and scattered caddis activity
- Carry BWOs for Sunday's and Monday's cool, wet conditions
- Streamer fish aggressively during rain, darker skies, and rising or slightly colored water
Top Patterns
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Hopper, size 8–12
- Ant or beetle, size 12–18
- Caddis dry or pupa, size 14–18
- BWO dry or emerger, size 18–22
- Olive, black, tan, or small white streamer
Blackfoot River
Conditions
The Blackfoot near Bonner is around 705 CFS, putting it slightly above its historical median for September 6. Early-morning water temperature was around 60 degrees, a substantial improvement from the warm-water concerns of August.
The river remains relatively low, but boulder water, riffles, banks, and deeper buckets should fish well. Sunday's and Monday's rain and clouds make the streamer game especially interesting.
Where to Fish
- Boulder edges and plunge pools
- Fast riffle edges
- Shaded banks and deeper buckets
- Foam lines below structure
- Grassy banks for terrestrial fishing
- Inside seams below heavier current
How to Fish It
- Prospect with hoppers and foam attractors along banks and boulder water
- Fish ants and beetles in softer edges
- Drop Frenchies, Perdigons, caddis pupa, or Pheasant Tails beneath the dry
- Look for Tricos and PMD spinners in softer morning water
- Streamer fish aggressively Sunday and Monday
- Use olive, black, tan, or white streamers depending on clarity
- Plan all floats around the active Weigh Station to I-90 closure
Top Patterns
- Hopper, size 8–12
- Ant or beetle, size 12–18
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Caddis dry or pupa, size 14–18
- Perdigon or jig nymph, size 14–18
- Olive, black, tan, or white streamer
Clark Fork River
Conditions
The Clark Fork has received a useful bump. Current readings are around 1,530 CFS above Missoula and 2,420 CFS below Missoula. That puts both gauges near or above their historical early-September averages and gives anglers more holding water than they had through much of August.
The Clark Fork could be particularly good Sunday and Monday. Cloud cover should help surface-feeding fish stay comfortable longer, while the increased water and dark skies improve streamer opportunities.
Where to Fish
- Soft slicks and tailouts during Tricos
- Riffle edges and foam lines
- Long inside seams
- Grassy banks and undercuts
- Side channels with depth and current
- Deep banks and structure during streamer conditions
How to Fish It
- Head hunt with Trico spinners when fish are visibly feeding
- Prospect terrestrials along grassy banks and islands
- Fish PMD spinners and caddis in slower seams
- Nymph riffle edges with Perdigons, Frenchies, and caddis pupa
- Carry BWOs during rain and persistent cloud cover
- Streamer fish deeper banks, buckets, and structure under darker skies
Top Patterns
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Hopper, ant, or beetle, size 8–18
- Caddis dry or pupa, size 14–18
- BWO dry or emerger, size 18–22
- Perdigon or Frenchie, size 14–18
- Olive, black, tan, or white streamer
Rock Creek
Conditions
Rock Creek near Clinton is around 390 CFS, up significantly from last week's roughly 255 CFS. Early-morning water temperature was around 57 degrees. That is a welcome combination of additional flow and cooler water.
The creek remains highly wadeable but should feel considerably less skinny. Cooler weather also makes it possible to fish methodically without racing the clock.
Where to Fish
- Riffle edges and oxygenated pocket water
- Boulder cushions and soft pockets
- Shaded willow edges and cutbanks
- Tailouts and slicks during Trico activity
- Foam lines below faster runs
- Deeper buckets during cloudy streamer windows
How to Fish It
- Fish Tricos and late PMD spinners in soft morning water
- Prospect hoppers, ants, beetles, and small attractors
- Use small dry-dropper rigs through pocket water
- Fish caddis pupa around riffle edges
- Carry BWOs during rainy and cloudy periods
- Streamer fish deeper pockets when skies darken
Top Patterns
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Caddis dry or pupa, size 14–18
- Hopper, ant, beetle, or attractor, size 8–18
- BWO, size 18–22
- Perdigon or Frenchie, size 14–18
- Olive or black streamer, size 4–8
West Fork of the Bitterroot
Conditions
The West Fork near Conner is around 336 CFS, well above its historical median for early September. Managed flows continue to make the West Fork one of the more stable smaller-water options in the Bitterroot drainage.
Where to Fish
- Shaded riffle edges below Painted Rocks
- Protected tailouts and inside seams
- Foam lines beside structure
- Deeper pockets below wood and boulders
- Soft glides during morning mayfly activity
- Overhanging grass and banks for terrestrials
How to Fish It
- Look for Tricos and PMD spinners in calmer water
- Prospect ants, beetles, and small hoppers along banks
- Fish small dry-dropper rigs through riffles and pockets
- Use longer leaders when trout are selective
- Carry small BWOs during wet, cloudy weather
- Make careful first casts before stepping into productive water
Top Patterns
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Caddis, size 14–18
- Small hopper, size 10–14
- Ant or beetle, size 12–18
- BWO, size 18–22
- Small olive streamer
Planning Note
Sunday and Monday: These are the weather days. Rain, clouds, and temperatures in the 60s should create some of the best streamer conditions we have had in weeks. Do not automatically leave the river at lunch. Fishing may improve as the day develops.
Tuesday: Cooler and brighter. Expect good morning mayfly activity followed by terrestrial and dry-dropper fishing.
Wednesday and Thursday: Warmer and sunnier. Shift back toward Tricos early, terrestrials through the morning, and more technical presentations during the brightest part of the day.
Friday: Another possible cloud-and-shower window. Keep streamers and BWOs handy.
Saturday: Comfortable early-fall weather. Tricos, terrestrials, caddis, and dry-droppers should cover most situations.
River Flow Snapshot – September 6, 2026
Values are the latest available instantaneous USGS readings reviewed September 6. USGS data are provisional and may change.
| River | Section | Gauge | Flow (CFS) | Status |
|---|---|---|---|---|
| Bitterroot | Upper | Near Darby (12344000) | 575 | Improved / Above Median |
| Bitterroot | Middle | Bell Crossing nr Victor (12350250) | 513 | Improved / Good September Shape |
| Bitterroot | Lower | Near Missoula (12352500) | 1,010 | Strong Improvement / Above Median |
| Blackfoot | Lower | Near Bonner (12340000) | 705 | Good September Flow / Float Closure Below Weigh Station |
| Clark Fork | Upper | Above Missoula (12340500) | 1,530 | Improved / Above Median |
| Clark Fork | Lower | Below Missoula (12353000) | 2,420 | Improved / Good Fall Transition Flow |
| Rock Creek | Lower | Near Clinton (12334510) | 390 | Improved / Excellent Wade Shape |
| West Fork Bitterroot | Lower | Near Conner (12342500) | 336 | Managed / Strong Smaller-Water Option |
This is the best regional flow picture we have had in several weeks. Combined with cooler weather, these increases should spread fish into more holding water and make the rivers substantially more forgiving than they were during the lowest August conditions.
Fly Box of the Week
Dry Flies
- Trico spinner, size 18–22
- PMD spinner, size 14–18
- Hopper, size 8–12
- Ant, size 12–18
- Beetle, size 12–16
- Caddis dry, size 14–18
- BWO dry or emerger, size 18–22
Nymphs
- Frenchie, size 14–18
- Perdigon, size 14–20
- Pheasant Tail, size 14–20
- Split Case PMD, size 14–18
- Caddis pupa, size 12–18
- Jigged Hare's Ear, size 14–18
- Small jig attractor, size 16–20
Streamers
- Olive streamer, size 4–8
- Black streamer, size 4–8
- Tan sculpin, size 4–8
- White baitfish pattern, size 4–8
- Woolly Bugger
- Sculpzilla
- Small articulated streamer
Hatch and Fly Chart – Early September Edition
| Hatch / Insect | Activity | Best Time | Recommended Fly | Size |
|---|---|---|---|---|
| Tricos | One of the most reliable current hatches | Morning | Spinner or cluster | 18–22 |
| PMDs | Late-stage spinner activity remains possible | Morning | Spinner, emerger, or nymph | 14–18 |
| Terrestrials | Hoppers, ants, and beetles remain major food sources | Late morning through afternoon | Hopper, ant, beetle, or foam attractor | 8–18 |
| Caddis | Still important around riffles and softer banks | Morning and evening | Dry, pupa, or soft hackle | 14–18 |
| BWOs | Worth watching during Sunday's, Monday's, and Friday's cooler cloud cover | Late morning through afternoon during clouds | BWO dry, emerger, or nymph | 18–22 |
| October Caddis | Early-season activity worth beginning to watch, especially on the Blackfoot | Variable | Large caddis pupa or attractor | 8–12 |
The key is not to abandon the late-summer flies too early. Tricos, terrestrials, PMDs, and caddis are still doing the heavy lifting. Cooler September weather makes BWOs and other fall insects increasingly worth carrying, but this week remains a transition rather than a full fall hatch program.
Gear Picks of the Week
Rain Shell
Sunday and Monday are exactly the kind of days when staying comfortable in wet weather can turn a mediocre outing into one of the better fishing days of the month.
Long Leaders and Fine Tippet
Trico fishing remains technical. Keep 5X and 6X available and be willing to lengthen the leader when targeting selective fish in slick water.
Streamer Box
For the first time in a while, the weather makes the streamer box a legitimate first-choice tool rather than something riding around in the boat out of habit.
Strategy and Expectations This Week
This is a noticeably better fishing setup than we had at the end of August. More water, cooler nights, rain, and cloud cover should make trout less concentrated and extend the usable fishing day.
The Bitterroot is the best overall choice this week. It has substantially more water, a good mix of Tricos and terrestrials, and excellent potential for streamers during the wet weather.
The Clark Fork may be the sleeper pick. Increased flows combined with Sunday and Monday cloud cover could create excellent feeding and streamer windows.
Rock Creek is the best wade-fishing option. The flow bump takes some of the August skinniness out of the creek while maintaining excellent accessibility.
The West Fork remains the most stable smaller-water choice. Managed flows are strong for this time of year.
The basic game plan: fish Tricos when trout are rising, use terrestrials and dry-droppers to cover water, and take advantage of every dark, rainy window with a streamer.
