Troy, MT Fishing Report: Kootenai, Koocanusa & Yaak — Week of October 22, 2026

Late October around Troy and Lincoln County is a quiet, low-water time to fish. The Kootenai River below Libby Dam is running cold and clear at about 4,500 cfs, the rainbow bite on Lake Koocanusa is picking up, and the Yaak River is low and clear. Here’s what dated reports from shops, USGS gauges, and Montana Fish, Wildlife & Parks are saying for northwest Montana (Region 1) this week.

Kootenai River (Libby Dam to Troy): USGS gauge 12301933 below Libby Dam read 4,550 cfs at 6:00 AM MDT on October 22, 2026 (provisional). Releases had held near 4,240 cfs from October 14 to 18, then stepped up to about 4,480 to 4,530 cfs from October 19 to 21. That’s a small bump, and flows are still between the 25th percentile (4,160 cfs) and the median (5,000 cfs) for this date, so wading access stays good. House of Fly’s Kootenai report dated October 15 said cooler weather has pushed water temperatures down and made the fishing less predictable. Nymphing is still the main game all day, with some dry-fly action in the warmest part of the afternoon. October caddis are finally hatching regularly and small mahogany mayflies are showing up. Small streamers cast to the bank and stripped away, or swung through tailouts and buckets, are also working. Linehan Outfitting’s October 6 report (carried by Montana Outdoor on October 8) expected releases near 4,000 cfs to hold through the end of the month and likely into November.

Downstream note: House of Fly reports the Leonia ramp closed for the season on October 15, as it does every year, and reopens June 1, 2027. The USGS gauge at Leonia read 4,690 cfs and about 52.5°F (11.4°C) early on October 22.

Lake Koocanusa: Chancy’s Fish Camp’s October 16, 2026 report (carried by Montana Outdoor on October 20) says the rainbow bite is picking up. They suggest trolling PlugIt Handcrafted Tackle plugs off planer boards and big flies, and note that darker colors can work well in the fall.

Yaak River: USGS gauge 12304500 near Troy read 81.2 cfs on October 22, 2026 (provisional). That’s well under the 25th percentile (129 cfs) and median (166 cfs) for the date, so expect skinny, clear water. We didn’t find a newer published conditions report for the Yaak this week, so ask at the counter for local intel.

Bull Lake and other Lincoln County lakes: we didn’t find a dated published report for Bull Lake or the smaller Lincoln County lakes this week. Stop in and we’ll share what local anglers are telling us.

Noxon Reservoir: Chancy’s October 16 report says pike fishing has been good, with nice fish up to 20 pounds. The walleye bite is still good near the lower end of the reservoir in 20 to 30 feet, and bass are in that depth range too. Nearby, Bitterroot Lake (by Marion) has low water that makes launching tough, but the rainbow bite is picking up on large flies and plugs, best from late afternoon to dark.

Flathead area

Chancy’s October 16 report says whitefish numbers are building on the Flathead River from the old steel bridge area up to the Columbia Falls bridge, with the run usually peaking in mid-November. Flathead Lake lake trout are heading into spawn mode; try big spoons along rocky shorelines in 15 to 30 feet from Halloween to Thanksgiving. Hungry Horse cutthroat have been good on small gold or copper spoons trolled a little faster. Chancy’s Fall Whitefish Festival entries are $10 for adults and free for kids 12 and under. Fall Mack Days on Flathead Lake has three weeks left and ends November 8; the Confederated Salish and Kootenai Tribes reported 16,798 lake trout turned in through Week 6.

Statewide notes

Western Montana rivers: Lightweight Fly Shop’s October 18 report (via Montana Outdoor, October 20) says flows across western Montana are low, clear, and cold, and the bite runs from about 11 a.m. to 4 p.m. Blue-winged olives are the main bug, with mahogany duns at midday and streamers as the season tightens. They called the back half of this week, after a Thursday front, the best BWO and streamer window.

Helena-area reservoirs (FWP, report of October 19): Canyon Ferry’s walleye bite has picked up again on the south end, and rainbows averaging 19 to 21 inches are hitting cowbells, spoons, and crankbaits. Holter and Hauser rainbows are good from shore. Boat docks have been pulled for the season, and Helena Valley Regulating Reservoir kokanee snagging runs through October 31.

Fort Peck (Don Wilkins, October 16): Smallmouth are on rocks from 10 to 35 feet, pike are in shallow weed beds on 1-ounce silver or copper spoons, and most lake trout are still in 120 to 135 feet.

Bighorn River (Bighorn Troutpost, October 19, via Montana Outdoor October 21): Lake turnover is settling, water is clearing at about 1,600 cfs below Afterbay and around 54°F, and nymphing has become more consistent.

Regulations: On October 19, Montana Outdoor carried FWP’s announcement that the Fish and Wildlife Commission approved the 2027-2028 fishing regulations, including a Flathead River drainage brown trout regulation. Always check current rules at Montana FWP fishing regulations before you go.

Heading out? Stop by Booze ‘N Bait in Troy for bait and tackle, and check our Best Fishing Days calendar to plan your trip.

Sources: USGS 12301933 Kootenai River below Libby Dam; USGS 12304500 Yaak River near Troy; House of Fly Kootenai River report, Oct. 15, 2026; Montana Outdoor, Linehan Outfitting Kootenai report, Oct. 8, 2026; Montana Outdoor, Chancy’s Fish Camp report, Oct. 20, 2026; Fall Mack Days Week 6 results; Western Montana Fly Report, Oct. 18-24; Helena Area Reservoirs Report 10.19.26; Fort Peck report 10.16.26; Bighorn River report, Oct. 21; FWP Commission fishing regulations. Conditions change fast, so treat this as a snapshot, not a guarantee.

Gear up at Booze ‘N Bait: bait & tackle · Montana fishing licenses · sporting goods · liquor store — 315 E Missoula Ave #1, Troy, MT · (406) 295-4415