Western Montana Fly Fishing Report
Important Blackfoot Access Update
The construction-related Blackfoot River floating closure below Weigh Station Fishing Access Site was lifted October 2.
The section from Weigh Station downstream through the Milltown area is once again open to floating. The closure had been in place since July 15 for BNSF railway bridge construction.
Current Restrictions and Regulations
Montana FWP currently lists no active emergency fishing or hoot-owl restrictions on the Bitterroot, Blackfoot, Clark Fork, Rock Creek, or West Fork Bitterroot.
- Blackfoot River: The temporary construction-related floating closure below Weigh Station has been lifted.
- Rock Creek: Fishing from boats or vessels is prohibited July 1 through November 30 under the regular fishing regulations.
- Other core rivers: No current emergency fishing restrictions affecting our normal western Montana fishing areas were listed when this report was prepared.
Regional River Conditions Overview
The rivers continue to drop and clear. This week's flows are noticeably lower than last week's, particularly on the upper Bitterroot, Rock Creek, and West Fork. The lower Bitterroot and Clark Fork remain the more forgiving larger-river options.
The biggest story is the weather. Stevensville and the Bitterroot Valley are forecast to reach the upper 70s and low 80s through much of the week despite cold nights. That combination should keep water temperatures comfortable while creating surprisingly strong afternoon terrestrial and October Caddis opportunities.
The better fishing window continues to run later. Expect slow starts after cold nights, then improving insect activity from roughly 10:00 a.m. through the afternoon. Saturday's cooler, potentially rainy weather should flip the program toward BWOs, Mahoganies, nymphs, and streamers.
Bitterroot River
Conditions
The Bitterroot is low, clear, and technical. Current readings are approximately 233 CFS near Darby, 474 CFS at Bell Crossing near Victor, and 899 CFS near Missoula. The lower river still has enough volume to provide a variety of productive water, while the upper river demands more careful boat handling, stealth, and attention to the deeper channels.
Warm afternoons should keep terrestrials relevant longer than we would normally expect this far into October. October Caddis remain important, while BWOs, Mahogany Duns, and Hecubas should be watched closely whenever clouds or cooler conditions develop.
Where to Fish
- Riffle edges dropping into deeper green water
- Foam lines and inside seams
- Tailouts and slicks with active fish
- Undercut banks with sufficient depth
- Side channels that still have meaningful flow
- Deeper buckets, shelves, and structure for streamers
How to Fish It
- Start later and let the river warm before expecting the best surface activity
- Watch slower water before casting; rising fish are increasingly selective
- Fish October Caddis adults or attractor-style dries through broken water
- Use ants, beetles, and smaller hoppers during warm afternoons
- Carry BWOs, Mahoganies, and Hecubas for softer light and cooler periods
- Fish Frenchies, Perdigons, Pheasant Tails, and October Caddis pupa beneath a dry
- Streamer fish deeper banks and shelves when wind, clouds, or lower light develop
Top Patterns
- October Caddis adult, size 8–12
- October Caddis pupa, size 8–12
- BWO dry or emerger, size 18–22
- Mahogany Dun, size 14–16
- Hecuba / Fall Drake, size 10–12
- Ant or beetle, size 12–18
- Small hopper, size 10–14
- Olive, black, or tan streamer
Blackfoot River
Conditions
The Blackfoot near Bonner is around 586 CFS. The river is low, clear, and concentrated into the better holding water. Spend more time fishing productive buckets, boulder seams, riffles, and shaded banks rather than covering every piece of shoreline.
The major change this week is access: the construction-related floating closure below Weigh Station was lifted October 2. Anglers can once again plan floats through the lower reach.
Where to Fish
- Deep boulder pockets
- Riffle edges
- Willow-lined banks with adequate depth
- Inside seams
- Deeper buckets
- Soft current breaks below heavier water
How to Fish It
- Fish October Caddis adults and pupa around riffles and broken water
- Use ants and beetles along warm, shaded banks
- Keep a smaller hopper or Chubby in the rotation during the warmest afternoons
- Fish BWOs when clouds or cooler weather arrive
- Use Zirdles, Rubber Legs, Frenchies, Perdigons, and caddis pupa beneath larger dries
- Streamer fish boulder seams, buckets, and banks
Top Patterns
- October Caddis adult or pupa, size 8–12
- BWO, size 18–22
- Mahogany Dun, size 14–16
- Hecuba, size 10–12
- Ant or beetle, size 12–18
- Zirdle / Rubber Legs, size 8–10
- Olive, black, tan, or white streamer
Clark Fork River
Conditions
The Clark Fork is around 1,335 CFS above Missoula and approximately 2,223 CFS below Missoula. These are lower than last week but still provide considerably more room and holding water than the smaller rivers.
The Clark Fork remains an excellent option for anglers who are willing to slow down and hunt individual fish. Long slicks, riffle edges, current tongues, foam lines, and side-channel seams deserve close attention before making a cast.
Where to Fish
- Riffle edges
- Foam lines
- Current tongues
- Long inside seams
- Tailouts and slicks
- Side-channel seams
- Deeper green lanes
How to Fish It
- Watch for feeding fish before casting
- Fish October Caddis through riffles and bank seams
- Use ants, beetles, and smaller hoppers during the warm afternoons
- Carry BWOs for clouds, drizzle, and Saturday's weather change
- Fish Mahogany Duns and Hecubas when larger mayflies appear
- Nymph Frenchies, Perdigons, Pheasant Tails, and caddis pupa through riffle edges
- Streamer fish banks, shelves, and soft inside seams when the light improves
Top Patterns
- October Caddis, size 8–12
- BWO dry / emerger, size 18–22
- Mahogany Dun, size 14–16
- Hecuba, size 10–12
- Ant, beetle, or hopper, size 8–18
- Frenchie or Perdigon, size 14–20
- Small to medium streamer
Rock Creek
Conditions
Rock Creek near Clinton is around 240 CFS. The creek is low, clear, and technical. Fish are easier to locate at these flows but easier to disturb, so stealth and good first casts matter.
Rock Creek remains an excellent fall wade-fishing option. October Caddis, remaining terrestrials, BWOs, Mahoganies, Hecubas, dry-droppers, and small streamers all have a place in the box.
Where to Fish
- Pocket water
- Boulder cushions
- Riffle drops
- Plunge pools
- Shaded undercuts
- Soft seams behind faster water
How to Fish It
- Move slowly and fish productive water before stepping into it
- Use October Caddis or larger attractors through broken water
- Fish smaller ants and beetles along warm banks
- Carry BWOs for cooler or cloudy periods
- Use small Perdigons, Frenchies, Pheasant Tails, and caddis pupa beneath dries
- Streamer fish plunge pools, deeper pockets, and undercuts
- Remember that fishing from boats or vessels is closed through November 30
Top Patterns
- October Caddis, size 8–12
- BWO, size 18–22
- Mahogany Dun, size 14–16
- Hecuba, size 10–12
- Ant or beetle, size 12–18
- Frenchie or Perdigon, size 14–20
- Small olive or black streamer
West Fork of the Bitterroot
Conditions
The West Fork near Conner is approximately 82 CFS on the latest verified reading. This is very low water and substantially different from the managed flows anglers enjoyed earlier in the season.
The West Fork is fishable, but it is no longer the easy smaller-water alternative. Expect limited depth, concentrated fish, and very clear water. The mainstem Bitterroot will generally provide more forgiving conditions this week.
Where to Fish
- The deepest available riffle edges
- Protected tailouts with adequate depth
- Deeper pools below structure
- Wood and boulder pockets
- Shaded banks with meaningful depth
How to Fish It
- Use long leaders and light tippet
- Stay out of productive water whenever possible
- Make careful first casts before moving closer
- Fish small mayflies and caddis patterns rather than oversized attractors in slick water
- Use ants and beetles during the warmest part of the afternoon
- Fish small Perdigons or Pheasant Tails in deeper pockets
- Consider the mainstem Bitterroot if you want more forgiving water
Top Patterns
- BWO, size 18–22
- Mahogany Dun, size 14–16
- Small October Caddis, size 10–12
- Ant or beetle, size 14–18
- Perdigon, size 16–20
- Pheasant Tail, size 16–20
- Small olive streamer
Planning Note
Sunday: Sunny and unusually warm. Start around 10:00 a.m. and expect the best action from late morning through afternoon. October Caddis and terrestrials should be more important than BWOs.
Monday: Potentially the warmest day of the week. This may feel more like September fishing than October. Ants, beetles, hoppers, October Caddis, and dry-droppers should all remain useful.
Tuesday through Thursday: Warm and sunny. Focus on riffles, seams, dry-droppers, October Caddis, and warm-afternoon terrestrials. Technical fish may require longer leaders and smaller patterns.
Friday: Still warm but potentially windier. Wind could improve terrestrial fishing and give streamers a better chance along banks and shelves.
Saturday: The week's major weather change. Cooler temperatures and possible rain could make this the best BWO, Mahogany Dun, and streamer day of the week.
Best overall strategy: Start late, fish the deeper water, use October Caddis and terrestrials while the sun is high, and be ready to shift toward BWOs and streamers when clouds or cooler weather arrive.
River Flow Snapshot – October 4, 2026
Values are the latest verified readings available when this report was prepared. Most are from October 4; Darby, Bell Crossing, and West Fork readings are from October 3. Gauge readings are provisional.
| River | Section | Gauge | Latest Verified Flow | Status |
|---|---|---|---|---|
| Bitterroot | Upper | Near Darby (12344000) | 233 CFS | Low / Technical |
| Bitterroot | Middle | Bell Crossing nr Victor (12350250) | 474 CFS | Low / Fishable |
| Bitterroot | Lower | Near Missoula (12352500) | 899 CFS | Best Mainstem Volume |
| Blackfoot | Lower | Near Bonner (12340000) | 586 CFS | Low / Clear / Closure Lifted |
| Clark Fork | Upper | Above Missoula (12340500) | 1,335 CFS | Solid Fall Option |
| Clark Fork | Lower | Below Missoula (12353000) | 2,223 CFS | Best Big-Water Option |
| Rock Creek | Lower | Near Clinton (12334510) | 240 CFS | Low / Clear / Technical |
| West Fork Bitterroot | Lower | Near Conner (12342500) | 82 CFS | Very Low / Highly Technical |
The clearest takeaway from this week's gauge block is that larger water is becoming increasingly attractive. The lower Bitterroot and Clark Fork offer substantially more usable habitat, while the upper Bitterroot, Rock Creek, and especially the West Fork require more deliberate fishing.
Fly Box of the Week
Dry Flies
- October Caddis, size 8–12
- BWO dry / emerger, size 18–22
- Mahogany Dun, size 14–16
- Hecuba / Fall Drake, size 10–12
- Elk Hair Caddis, size 14–18
- Ant, size 12–18
- Beetle / small hopper, size 10–18
Nymphs
- October Caddis pupa, size 8–12
- Frenchie, size 14–18
- Perdigon, size 14–20
- Pheasant Tail, size 14–20
- BWO nymph, size 18–22
- Jigged Hare’s Ear, size 14–18
- Zirdle / Rubber Legs, size 8–10
Streamers
- Thin Mint
- Sculpzilla
- Sparkle Minnow
- Woolly Bugger
- Mini Dungeon
- Small olive sculpin
- Black or tan streamer
Hatch and Fly Chart – Early October Edition
| Hatch / Insect | Activity | Best Time | Recommended Fly | Size |
|---|---|---|---|---|
| October Caddis | Primary large fall insect across the region | Late morning through afternoon | Adult, pupa, or large attractor | 8–12 |
| BWOs | Best during cooler, cloudy, damp conditions | Late morning through afternoon | BWO dry, emerger, or nymph | 18–22 |
| Mahogany Duns | Important fall mayfly, especially when conditions soften | Late morning through afternoon | Mahogany dry, cripple, or emerger | 14–16 |
| Hecubas | Still worth carrying, especially in broken water | Late morning through afternoon | Hecuba or Brindlechute | 10–12 |
| Small Caddis | Still present around riffles and soft seams | Variable | Elk Hair Caddis, X-Caddis, pupa | 14–18 |
| Terrestrials | Unusually relevant this week because of warm afternoon weather | Afternoon | Ant, beetle, small hopper | 10–18 |
Do not put the terrestrial box away yet. With afternoon temperatures approaching 80 degrees through much of the week, ants, beetles, and hoppers can still matter. The colder, potentially wet Saturday forecast should shift the advantage sharply toward BWOs and streamers.
Gear Picks of the Week
Long Leaders
Low, clear water is exposing every sloppy presentation. Nine-foot leaders are a starting point, not necessarily the finished product.
4X–6X Tippet
Fine tippet matters on slick water and selective fall fish. Carry enough options to adjust rather than trying to force one setup through every situation.
Streamer Rod
Keep it rigged even on sunny days. Wind, shade, or Saturday's weather change can create a streamer opportunity quickly.
Strategy and Expectations This Week
The Bitterroot remains our best overall recommendation. Favor the middle and lower river where additional water creates more holding habitat.
The Clark Fork is increasingly attractive. More water gives anglers more options than the smaller rivers, and patient dry-fly anglers can find excellent fall fishing.
The Blackfoot is back in play from an access standpoint. The Weigh Station construction closure has been lifted, opening lower-river float options again.
Rock Creek remains a good wade option but requires stealth. At 240 CFS, expect clear water and selective fish.
The West Fork is extremely low. At roughly 82 CFS, recommend it primarily to anglers specifically looking for highly technical small-water fishing. For most customers, the mainstem Bitterroot is the better choice.
