Tailwater · Mixed · Montana, US

Kootenai River

Kootenai River — 18205 Lake Koocanusa
Tomorrow · Not the day for it
Czech Nymph
Forecast · Tomorrow
Not the day for it
Not much stacked in your favour today. Worth an hour if you are nearby, not worth the special trip.
45% projected
Today's fly
Czech Nymph
Czech Nymph
Conditions on the water · Tomorrow
Live gauge
Level
Rising
5.80 m
Lifting fast
Water temp11.5°C
ClarityUnfishable
Weather13°C
WindN 3 km/h
Pressure1021 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Rainbow Trout
Ideal
12°C est.ideal 10–18°C
0°14°28°
How to fish it · for Rainbow Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Excellent — water temperature is right today, though time of day could be better.
Likely species
Mayflies
terrestrials
Hatch timeline · tomorrowPeak at 11am

12pm(now) — Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 63%
Also:Black Midge29%
Peak emergence windowWeather boost8 food groups active

Peak activity at 11am — Western Blue-Winged Olive (Western Blue-Winged Olive, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2
TricoHatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Rainbow Trout fly box
Permits & access
Permit required — see local rules.
  • Montana licence
  • Bull trout must not be targeted and must be released (federally threatened)
  • Fishability is set by the Libby Dam release, not the weather.
What's coming
Plan ahead
5-day outlook
Gallery · 2
  1. Kootenai River — 18205 Lake Koocanusa
    18205 Lake Koocanusa
  2. Terrain map of the venue
    Terrain map
Conservation note

Wild rainbow trout (including native redband lineage) are the headline. Native westslope cutthroat and federally threatened bull trout are also present: bull trout must not be targeted and must be released unharmed. The pack's 'cutthroat_trout' profile is a Phase 1 deliverable and there is no bull_trout scoring profile by design.

Water quality · US Clean Water Act
  • Aquatic life: Impaired
What this classification means

EPA ATTAINS assessment unit 'Kootenai River' (MT76D001_010), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Temperature, Hydrologic Alteration. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · MT76D001_010

The full read · show the working · for Rainbow Trout · confidence 90%
How the 81 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity62 × 12%7.4
Conditions total= 81
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts