Freestone · Mixed · Montana

Clark Fork

Wide view of a gravel road crossing the Clark Fork River on a bridge, with a road sign reading Clark Fork River, cottonwoods and mountains in the background
Marginal · Brown Trout
Parachute Adams · 12-18
Marginallive now
Slow going — pick your moments
River temperature is the limiting factor today, not the flow. Fish dawn or dusk if you go at all, and handle everything with extra care.
80% confidence
What moved it
  • Level0.78 mDropping after lift
  • Water temp19.3°C
  • ClarityClear
Today's fly
Parachute Adams
Parachute Adams12-18
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
0.78 m
Dropping after lift
Water temp19.3°C
ClarityClear
Weather21°C
WindSW 8 km/h
Pressure1014 hPa
Rain · recent2.6 mm
Rain · ahead0.0 mm

Live readings — water temperature is an estimate where the gauge does not record it.

Water temperature for Brown Trout
Warm — slow
19°C est.ideal 1016°C
0°14°28°
How to fish it · for Brown 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
Water at 19.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 2 active hatches hour by hour with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 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
Brown Trout fly box
Permits & access
Permit required — see local rules.
  • Montana licence
  • Check FWP for hoot-owl (afternoon) closures on the lower river in hot summers.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Wide view of a gravel road crossing the Clark Fork River on a bridge, with a road sign reading Clark Fork River, cottonwoods and mountains in the background
    The Clark Fork River, Powell County, Montana
  2. Terrain map of the venue
    Terrain map
Water quality · US Clean Water Act
  • Aquatic lifeImpaired
  • RecreationImpaired
What this classification means

Recreation: Bacteria/pathogen advisory — mind wading cuts and immersion.

EPA ATTAINS assessment unit 'Clark Fork River' (MT76E001_010), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Nutrients, Algal Growth, Habitat Alterations, Metals Other Than Mercury, Mercury. 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) · MT76E001_010

The full read · show the working · for Brown Trout · confidence 80%
How the 32 is built — score × weight = contribution
Temperature35 × 28%9.8
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
Directions
Seasons & zones
  • TroutThird Saturday of MayLast day of February
Related guides
Booking & contacts