Kootenai River
Libby Dam Tailwater · NW Montana
NW Montana, USA
Open live forecast →Target species: Rainbow, Brown, and Bull Trout.
Stream gauge: 12301933. Flow and water temperature update on every refresh.
Weekly AI Outlook as of 06/05/26
The Kootenai is firing at 25,100 cfs — triple the typical June flows, creating a completely different river than the seasonal context suggests. This high water pushes fish to structure and makes wading treacherous, but the cooler flows keep water temps ideal for extended feeding windows. PMDs and caddis are active in the 52-60°F range, though you'll need to adjust tactics for the big water. Focus on weighted nymphs in the softer water behind boulders and log jams.
- Flow: 25,100 cfs — much higher than typical June range of 4,000-8,000 cfs. Fish pushed to structure, limited wade access.
- Hatches: PMDs emerging midday in slower pockets, caddis active evenings. High water disperses rises but bugs are coming off.
- Water Temp: Holding 52-60°F range despite high flows. Cool enough for all-day feeding, warm enough for steady insect activity.
- Best Window: Midday PMD emergence 11am-2pm, evening caddis from 6pm. High water extends prime fishing hours.
Generated weekly from live USGS gauge readings, weather forecasts, and recent fly shop reports. Updates Friday mornings.
About this Water
- Tailwater
- Best months: May–Oct, peak June–Sept
The Kootenai River below Libby Dam in northwest Montana is a major tailwater fishery, producing large rainbow trout in big, broad water through dramatic mountain country. The river is too big to wade except at limited access points — float trips dominate. The cold, consistent releases from Libby Dam create classic tailwater conditions: dense midge hatches, reliable PMD and caddis activity, and strong streamer fishing for trophy browns through fall. The 'Dunn Creek' and 'Kootenai Falls' reaches each offer distinct character.
The Kootenai produces the largest documented rainbow trout in Montana — fish exceeding 30 inches and 15+ pounds are caught annually below Libby Dam.
January Outlook
The Kootenai below Libby Dam is one of Montana's coldest and most underrated tailwater fisheries. Midge activity on mild days for determined anglers in this remote NW Montana setting.
Productive Patterns
- Zebra Midge
- RS2
- WD-40
- Juju Baetis
Tips
Target the Troy to Libby section where access is best. The tailwater stays open year-round. Few anglers fish the Kootenai in January — the fish are undisturbed. Midday window 11am–2pm.
Water Notes
Regulated by Libby Dam. 3,000–7,000 cfs. Very cold 38–44°F in winter. One of the coldest tailwaters in Montana.
February Outlook
February midging on the Kootenai. The dam-regulated flows provide consistent year-round conditions rarely seen in NW Montana's rugged terrain.
Productive Patterns
- Zebra Midge
- RS2
- Midge Pupa
- WD-40
Tips
Fish the slow inside bends between Libby and Troy. The Kootenai's size and volume can be intimidating — a guide is worthwhile for first visits. Target slower current seams.
Water Notes
3,000–6,000 cfs. Water 38–44°F. Constant dam regulation. Open year-round.
March Outlook
BWO activity begins on warm afternoons. The Kootenai transitions from winter to spring with consistent hatches that make it one of Montana's best-kept secrets.
Productive Patterns
- Sparkle Dun #20
- RS2
- BWO Nymph
- Zebra Midge
Tips
March BWO hatches on the Kootenai are exceptional — the river's cold, clear tailwater conditions support dense hatch activity. 11am–2pm is prime. Fish the flats between Libby and Troy.
Water Notes
3,000–7,000 cfs. Water 42–50°F. The tailwater insulates against early runoff. Prime spring setup.
April Outlook
Consistent BWO and PMD hatches. The Kootenai's tailwater character keeps it in prime condition while other Montana rivers are in runoff. Outstanding late April fishing.
Productive Patterns
- PMD Sparkle Dun
- BWO Parachute
- Elk Hair Caddis
- Soft Hackle
Tips
April is arguably the Kootenai's best month — the dam prevents runoff impact and the hatches are consistent and prolific. Float fishing is the most effective approach given the river's size.
Water Notes
3,500–6,000 cfs. Water 46–54°F. Protected from runoff by Libby Dam.
May Outlook
PMD and Caddis hatches. Excellent spring fishing on a large river that rewards serious anglers. One of the most underrated May rivers in the state.
Productive Patterns
- PMD Cripple
- Elk Hair Caddis
- PMD Sparkle Dun
- Soft Hackle Emerger
Tips
May evenings with caddis hatches on the Kootenai are exceptional. Float between Libby and Troy for best access. Large rainbow and bull trout are the targets.
Water Notes
4,000–8,000 cfs. Water 50–58°F. Excellent spring conditions.
June Outlook
Golden Stone and Caddis season. The Kootenai is one of Montana's finest June fisheries — large fish, prolific hatches, and remarkably little pressure for its quality.
Productive Patterns
- Golden Stone
- Elk Hair Caddis
- PMD
- Stimulator
Tips
June on the Kootenai is extraordinary — the evening caddis hatches produce fish rising across the entire river surface. Float the full section for the best experience.
Water Notes
4,000–8,000 cfs. Water 52–60°F. Excellent summer conditions building.
July Outlook
Hopper-dropper and Trico fishing. The Kootenai's size creates challenging but rewarding terrestrial fishing with large rainbow and brown trout.
Productive Patterns
- Hopper-Dropper
- Trico Spinner
- Elk Hair Caddis
- PMD Cripple
Tips
Float the river for best hopper coverage. Trico spinner falls in the flat water sections early morning are spectacular. The Kootenai's large fish are world-class but require precise presentations.
Water Notes
3,500–7,000 cfs. Water 56–64°F. Float fishing recommended.
August Outlook
Consistent hopper-dropper fishing and Trico mornings. The Kootenai's cold tailwater keeps fish healthy through summer heat when other rivers suffer.
Productive Patterns
- Hopper
- Trico Spinner
- Elk Hair Caddis
- Stimulator
Tips
The Kootenai's tailwater temperatures are a distinct advantage in August. Fish remain active and healthy. Hopper fishing along the bank edges is excellent.
Water Notes
3,000–6,000 cfs. Water 56–63°F. Cold tailwater maintains excellent summer conditions.
September Outlook
Excellent fall fishing with BWO hatches returning and large rainbow trout very active. The Kootenai is exceptional in September with dramatically reduced pressure.
Productive Patterns
- Blue Winged Olive
- Hopper
- Streamer
- Mahogany Dun
Tips
September on the Kootenai is a genuine discovery for Montana anglers — world-class fishing with almost no company. Float the Troy section and work the evening BWO hatches.
Water Notes
2,500–5,000 cfs. Clear and cold 52–60°F. Prime fall tailwater conditions.
October Outlook
Brown and rainbow trout streamer fishing. Fall BWO hatches continue. The Kootenai in October is one of Montana's finest but least-visited fall fisheries.
Productive Patterns
- Articulated Streamer
- Blue Winged Olive
- Copper John
- Soft Hackle
Tips
Work the deep pools and gravel bars with streamers in the morning. BWO hatch 11am–3pm on overcast days is excellent. Large fish are very aggressive in October.
Water Notes
2,500–5,000 cfs. Water 44–54°F. Excellent fall tailwater conditions.
November Outlook
Midge fishing on the Kootenai tailwater. Cold November but the regulated flows stay open. One of the few NW Montana rivers that fishes in November.
Productive Patterns
- Zebra Midge
- RS2
- WD-40
- Juju Baetis
Tips
The 11am–2pm window is key. Fish the slow tailout pools between Libby and Troy. November pressure is essentially zero on this remote river.
Water Notes
2,500–5,000 cfs. Cold 40–48°F. Stable dam-regulated flows. Open year-round.
December Outlook
Year-round tailwater fishing. The Kootenai below Libby Dam is one of Montana's most consistent winter fisheries. Midge activity in the deep pools.
Productive Patterns
- Zebra Midge
- Mercury Midge
- RS2
- WD-40
Tips
Target the 11am–2pm warming window. The section near Troy has the best winter access. Few anglers fish the Kootenai in December — a completely uncrowded world-class river.
Water Notes
2,500–5,000 cfs. Water 38–44°F. Constant flows from Libby Dam. Open all winter.
Hatch Calendar
| Insect | Peak | Active | Size | Productive Patterns |
|---|---|---|---|---|
| Midge Chironomidae |
Jan, Feb, Mar, Nov, Dec | Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec | #18–22 |
|
| Blue Winged Olive Baetis tricaudatus |
Apr, Oct | Mar, Apr, May, Sep, Oct, Nov | #18–22 |
|
| Pale Morning Dun Ephemerella inermis |
Jul | Jun, Jul, Aug | #16–18 |
|
| Caddis Hydropsyche / Brachycentrus spp. |
Jul, Aug | May, Jun, Jul, Aug, Sep | #14–18 |
|
| Trico Tricorythodes spp. |
Aug | Aug, Sep | #20–24 |
|
| Hoppers Acrididae / Tettigoniidae |
Aug | Jul, Aug, Sep | #8–12 |
|
Access & Approach
Libby is the primary base. Limited wade access — float trips dominate. Montana fishing license required; bull trout catch-and-release only with mandatory identification skills.
Nearby Fly Shops
- Kootenai Angler
- Linehan Outfitting
Regulations & License
Fishing in Montana requires a current license. Always verify season dates, bag limits, and any special-regulation waters before you fish.
Montana fishing regulations & license →
Nearby Waters
Closest Waters
More in This Region
About Current
Kootenai River conditions on Current combine real-time flow data (USGS, WSC, CDEC, CEHQ), weather, tide predictions, hatch probabilities calibrated to this specific water, and recent fly shop reports from the area.
Kootenai River is one of 245 hand-curated waters in Current. The app and web forecast also generate AI outlooks for any unlisted river, lake, or saltwater flat anywhere in the world — drop a pin or paste a name and Current produces a fresh seasonal outlook with weather, flow context, and recommended techniques.
Open the live forecast for today's numbers and the 7-day outlook, or download the iOS app to carry it with you on the water.