Troutline

Kootenai River

Montana·Northwest Montana·48.41° N, 115.55° W
Flow
9,100 CFS
Kootenai River bl Libby Dam nr Libby
Water Temp
58°F
Kootenai River at Leonia, ID
Condition
Below Normal
Weather
69°F
Chance Light Rain
near Libby

Insights

Water Temp
Water 58°F — prime
Active-feeding window.
Wind
Wind 0 mph — calm
Easy casting and clean surface presentations.
Flow
Low flows at 9,100 CFS
Fish are spooky. Lighten tippet and lengthen leaders.

The Kootenai is Montana's biggest tailwater, and it fishes nothing like the crowded blue-ribbon rivers three hours south. Below Libby Dam the river runs wide, cold, and clear year-round — Lake Koocanusa releases hold temperature and flow steady enough that Pale Morning Duns and caddis come off on schedule and the wild rainbows keep looking up. These aren't stocked fish. They're a native inland redband strain that has been in this watershed a very long time, and while the average fish runs a modest 12–16 inches, the river grew the Montana state-record rainbow: 33 pounds, 38 inches, caught below the dam in 1997. FWP manages the top reach as a trophy fishery on purpose, with a 28-inch minimum on rainbows and a new single-hook rule, so the ceiling is real.

It's mostly a float fishery, and mostly a dry-fly one. From the dam down to the Idaho line there's roughly 40 miles of drift-boat water, big and pushy enough that wading is a lower-water, early-spring or late-fall proposition rather than the everyday approach. The catch is the dam itself: releases fluctuate — sometimes sharply and without much warning — for power generation and the spring sturgeon-recovery pulse, so flows that were friendly in the morning can stack up by afternoon. Good floating generally lines up in the 8,000–12,000 CFS window; the river doesn't blow out muddy the way a freestone does, but a big scheduled release changes the wade game and the safety picture in a hurry. Watch the gauge, not just the forecast.

The other thing you're buying up here is solitude. This is the far northwest corner of the state — Libby and Troy, closer to the Idaho panhandle and Canada than to Bozeman — and even in peak July through October you'll share the water with only a couple other boats a day. Kootenai Falls splits the river partway down: a genuine, unrunnable waterfall you take out well above, with most of the trophy trout water sitting upstream between the dam and the falls and China Rapids' deep pools in between. Bull trout are present and fully protected — you'll hook the occasional one, and it goes back immediately.

Species

  • Redband Trout
    Primary · Jul-Oct · 12-16" (to 20"+)

    Wild native inland redband rainbow — the fishery. FWP manages the Libby Dam reach as a trophy fishery; the state record (33 lb, 38") came from below the dam in 1997.

  • Westslope Cutthroat Trout
    Common · Jun-Sep · 8-14"

    Native, mixed in with the rainbows; more common in the upper reaches and tributaries.

  • Bull Trout
    Present · — · 18-30"+

    Native and ESA-listed — closed to angling. Release any incidental catch immediately, with little or no delay.

  • Mountain Whitefish
    Abundant · Year-round · 10-16"

    Native and plentiful; strong on nymphs. A state-record whitefish came from this river.

  • Brown Trout
    Occasional · Sep-Nov · 12-18"

    Uncommon — the odd fish shows up, not a target species here.

Ideal wading flow2,500–7,000 CFS
Blow-out>14,000 CFS
Ideal water temp48–60°F

Summer (Jul–Aug) for consistent PMD and caddis dry-fly fishing, then fall (Sep–Oct) for hoppers, BWOs, and streamers. Spring (Mar–May) brings streamers and early BWOs at lower, more wadeable flows. As a tailwater it doesn't blow out muddy — the risk is a sudden scheduled dam release spiking flows fast, which changes wade safety more than clarity. Prime floating water is roughly 8,000–12,000 CFS; check the live gauge before committing to a wade.

Sections

3 sections on this river

Kootenai Falls to Idaho Border (Troy to Leonia)

FloatRainbow Trout · Whitefish

Below the falls the river drops to the lowest elevation in Montana — lower gradient, passing Troy and the Yaak River confluence before crossing into Idaho at Leonia. Quieter, less-fished water; being lower and warmer, it fishes better in spring and fall than in midsummer.

Best for: Rainbow trout and mountain whitefish; a cooler-season float. The USGS Leonia gauge anchors the downstream end and provides the river's only live water temperature.

Libby to Kootenai Falls (China Rapids)

FloatCutthroat · Rainbow Trout · Whitefish

Below Libby the river narrows into rapids and deep pools with fewer access points. China Rapids holds excellent fishing in its deep pools and is some of the best dry-fly water on the river. Take out well above Kootenai Falls — an unrunnable waterfall.

Best for: Dry-fly fishing to rainbow trout and westslope cutthroat trout; nymphing the deep pools for whitefish.

Libby Dam to Highway 37 Bridge (Trophy Reach)

FloatRedband · Rainbow Trout · Whitefish

Wide, fast, cold tailwater with side channels and braids straight off Libby Dam — big, pushy water where the giant redband rainbow trout live. This is the state-record reach, managed as a trophy fishery with a 28-inch rainbow minimum and a single-hook restriction. Watch for dam-release fluctuations.

Best for: Wild redband rainbow trout on dries (PMD, caddis) and nymphs; streamers in early spring. Mountain whitefish on nymphs throughout.

Regulations

Current fishing rules and restrictions

Managed as a trophy rainbow trout fishery on the Libby Dam reach, with a 28-inch rainbow minimum, a new single-hook restriction below the dam, and bull trout fully protected. Applies within Montana FWP's Western Fishing District.

  • Rainbow trout: 1 daily / 1 in possession, 28-inch minimum length (trophy management, Libby Dam reach)
  • Single-pointed-hook restriction from Libby Dam downstream to the Highway 37 Bridge near the Fisher River
  • Bull trout: closed to angling — release immediately, with little or no delay (ESA-listed)
  • White sturgeon: protected/closed (ESA-listed Kootenai population)
  • Season on the Libby Dam → Hwy 37 Bridge reach: June 1 – February 28
  • Montana fishing license required (resident/nonresident tiers via FWP)

The single-hook rule was adopted for the 2025–2026 regulations. Verify current-year specifics before your trip — Montana regs change annually, and season dates on reaches downstream of the Hwy 37 bridge may follow the general Western District standard.

Source: Montana Fish, Wildlife & Parks — Western Fishing District. Regulations change annually — verify before fishing.

Access & Logistics

Getting there, fly shops, and lodging

Getting There

Libby, MT

~2 hrs from Kalispell, ~2.5-3 hrs from Spokane, WA

Camping & Lodging

Bureau of Reclamation park and camping at Libby Dam; campgrounds along Highway 37 and at the Yaak River confluence; cabins at Kootenai Angler and Linehan Outfitting. Full services in Libby (county seat) and Troy.

Abundant public access and boat ramps line Highway 37 from Libby Dam downstream through Libby and on toward the Idaho border. Kootenai Falls, between Libby and Troy, is an unrunnable waterfall — know your take-out well above it. Watch for sudden scheduled dam releases (power generation and the spring sturgeon pulse), which can raise flows fast and change wade safety.

Conditions data is live from public monitoring networks. Regulations change annually — always verify current rules with your state fish & wildlife agency before fishing.

More in Montana

View all 22 rivers

Northwest Montana

Flathead RiverMT

The big glacial-green valley river formed where the three forks meet near West Glacier, running through the Flathead Valley into Flathead Lake and continuing below Kerr Dam. A native westslope cutthroat dry-fly float up top, northern pike water down low.

Middle Fork Flathead RiverMT

Wild & Scenic glacier-fed freestone forming the southern boundary of Glacier National Park. A catch-and-release native westslope cutthroat fishery — attractor dries and dry-droppers once runoff clears in mid-July.

North Fork Flathead RiverMT

Remote Wild & Scenic snowmelt river forming Glacier National Park's western boundary along the Canadian border. A catch-and-release native westslope cutthroat fishery — gravel-bar wading and raft floats on attractor dries once runoff clears in mid-July.

South Fork Flathead RiverMT

A legendary Bob Marshall Wilderness cutthroat river above Hungry Horse Reservoir — the best pure-strain westslope cutthroat fishery in the Lower 48, reached only by horseback, foot, or fly-in raft. A separate roadside tailwater fishes below the dam.

Other regions

Beaverhead RiverMT

The premier Dillon-area tailwater below Clark Canyon Dam, famous for oversized, technical brown trout in tight, willow-lined water. Cold summer releases keep the upper river fishing all season, but heavy irrigation dewatering and repeated drought closures shape the lower river.

Big Hole RiverMT

The 'Last Best River' — 153 miles of classic Montana freestone from the Beaverhead Mountains through Wisdom, Wise River, and Glen to its confluence with the Beaverhead at Twin Bridges. Home to the lower 48's only fluvial Arctic grayling population.

Bighorn RiverMT

The Yellowtail Dam tailwater — 13 miles of fly fishing gold from the Afterbay to Two Leggins. 3,000-5,000 trout per mile, year-round consistent flows, and the West's most reliable sow bug and PMD fishery.

Bitterroot RiverMT

Western Montana's home water — 84 miles of cottonwood-bottomed valley fishing for wild rainbows, browns, and native westslope cutthroat. Famous for the March-April Skwala stonefly hatch and a long dry-fly season from spring through October.

Blackfoot RiverMT

The freestone river Norman Maclean made famous, rebuilt over 30 years of restoration into a genuinely wild fishery for westslope cutthroat, browns, and rainbows east of Missoula. No dam on the mainstem, a legendary June salmonfly hatch, and a boulder-strewn canyon corridor that fishes best from a drift boat.

Clark Fork RiverMT

Montana's longest river fishes like three waters in one — a skinny Superfund-recovery meadow stream up around Deer Lodge, a legitimate mid-size freestone through Missoula, and big float water down to St. Regis. Wild browns up top, 16-17" rainbows and cuttbows below town, and a marquee mid-September dry-fly window.