The Bitterroot is in a clear, technical early-October pattern. The lower river near Missoula is running around the upper 800s cfs, down from the last report’s 899 cfs range and continuing to settle after September’s rain bumps. That drop means the river is becoming a little more demanding again, but flows are still much healthier than the low-water stretch we saw in late summer. Fish have enough water to use banks, riffles, seams, and tailouts, but they will reward careful presentations more than fast covering.

Focus on riffle edges, foam lines, inside seams, soft buckets, undercut banks, tailouts, side channels, and deeper green lanes. Dry-dropper rigs remain a strong search setup, especially with a terrestrial or October Caddis-style dry on top and a small mayfly, caddis, or jig nymph underneath. In slower slicks and tailouts, take a minute to watch before casting. If fish are visibly feeding, a single dry on a longer leader will usually be cleaner than a heavier dry-dropper rig.

The fall hatch transition is now the main story. There is still a good chance to find fish on terrestrials, especially beetles, ants, and hoppers along grassy banks, brushy edges, and cutbanks. That said, the terrestrial window is slowly shrinking as cooler nights become more consistent. Keep a close eye out for BWOs during cloudy or damp periods. October Caddis are already being seen, and Mahogany Duns and Hecubas should continue becoming more important as we move deeper into October.

The weekend outlook is pleasant and fairly warm for the season. Saturday looks sunny and mild, and Sunday warms back into the upper 70s around Hamilton. Cool nights should keep water temperatures comfortable, while warmer afternoons may keep terrestrials and October Caddis dries relevant near the banks.

Streamer fishing is worth mixing in as we move further into fall. Cooler water, shorter days, and low-light windows can make better fish more willing to chase. Work small sculpins, Thin Mints, Woolly Buggers, Sparkle Minnows, and modest articulated patterns along banks, shelves, and deeper seams.

What's Working

Dry Flies

• Hoppers #8-12

• Ants #12-18

• Beetles #12-16

• Chubby Chernobyls #8-14

• Water Walkers #8-12

• BWO Dries #18-22

• Elk Hair Caddis #14-18

• X-Caddis #14-18

• October Caddis Adults #8-12

• Mahogany Duns #14-16

• Hecubas #10-12

• Purple Haze #14-20

• Parachute Adams #14-20

Nymphs

• Frenchies #14-18

• Pheasant Tails #14-20

• Perdigons #14-20

• BWO Nymphs #18-22

• Caddis Pupa #12-18

• October Caddis Pupa #8-12

• Jigged Hare’s Ears #14-18

• Prince Nymphs #12-16

• Small jig nymphs #16-20

Streamers

• Sparkle Minnows

• Mini Dungeons

• Sculpzilla

• Thin Mint

• Woolly Buggers

• Small sculpin patterns

• Olive streamers

• Black streamers