Freestone · Mixed · Montana

Flathead River

A calm, glassy stretch of the Flathead River lined with rocky banks and autumn-coloured trees near Glacier National Park, Montana.

The Flathead is one of the most beautiful rivers in Montana — three forks of cold, jade-clear snowmelt draining the country along Glacier's western edge.

Good · Rainbow Trout
Parachute Adams · 12-18
Goodlive now
A proper day on the water
River high but settled. Match the colour and fish the seams.
75% confidence
What moved it
  • Level1.72 m
  • Water temp17.0°C
  • ClarityClear
Today's fly
Parachute Adams
Parachute Adams12-18
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
1.72 m
Water temp17.0°C
ClarityClear
Weather29°C
WindSW 7 km/h
Pressure1009 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

Live readings only. Trends shown where the gauge supports them.

Water temperature for Rainbow Trout
Ideal
17.0°Cideal 1018°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
Good — water temperature is working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 5 active hatches hour by hour with Pro.

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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

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
2
1
1
2
2
2
2
2
2
2
Western Green DrakeHatch
2
2
Flav (Small Western Green Drake)Hatch
2
3
2
Mahogany DunHatch
2
2
American March BrownHatch
2
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)
  • Check FWP and Glacier NP boundary-water rules on the North and Middle forks.
What's coming
Plan ahead
5-day outlook
Gallery · 2
  1. A calm, glassy stretch of the Flathead River lined with rocky banks and autumn-coloured trees near Glacier National Park, Montana.
    Flathead River - Calm Morning
  2. Terrain map of the venue
    Terrain map
About this water

The Flathead is one of the most beautiful rivers in Montana — three forks of cold, jade-clear snowmelt draining the country along Glacier's western edge. The North and Middle forks fish like big wilderness freestones for native westslope cutthroat; the main stem below the forks is broad float water. It blows out brown in the spring melt and then settles into a long, clear summer of cutthroat on dries. Read the river, not the sky, only insofar as you watch the snowpack come off — once the runoff clears, it's a generous, forgiving fishery.

Under the surface

The Flathead comes off the high country along the western edge of Glacier in three forks — North, Middle and South — that gather into one big, cold, improbably clear river above Flathead Lake. The water carries the milled-down colour of the Belt argillite it runs over, a pale jade-green that lets you count cobbles in six feet of water. The North Fork traces the park boundary through lodgepole and cottonwood; the Middle Fork bangs through canyon and boulder along Highway 2; the main stem below the forks is broad, braided and gravel-floored. This is snowmelt water — it comes up hard and dirty in the May and June melt and then drops into a long, clean summer. The wading is honest gravel and cobble, but the river is bigger and colder than it looks, and the clarity flatters the depth.

Wading: Deceptive depth in very clear, cold snowmelt water

  • Mixed
  • Partly confined
  • Plane bed
  • Pool riffle
Conservation note

Headline fish is native westslope cutthroat (Oncorhynchus clarkii lewisi) — handle minimally and release. Native bull trout (Salvelinus confluentus) are present and federally threatened: targeting is prohibited and any hooked by accident must be released unharmed. The pack's 'cutthroat_trout' species/scoring profile is a Phase 1 deliverable; until seeded it will not score. There is no bull_trout scoring profile by design — it must not be presented as a target species.

Water quality · US Clean Water Act
  • Aquatic lifeNot assessed
What this classification means

EPA ATTAINS assessment unit 'Flathead River' (MT76O001_010), 2021 Integrated Report. Aquatic Life use: Not Assessed. 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) · MT76O001_010

The full read · show the working · for Rainbow Trout · confidence 75%
How the 79 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time40 × 13%5.2
Pressure75 × 7%5.3
Insect activity63 × 12%7.6
Conditions total= 79
Can you trust it?
Water temperaturelive gauge readinggauge
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
Seasons & zones
  • Trout Third Saturday of MayLast day of February
Related guides
Booking & contacts