Freestone · Mixed · Montana, US

Big Hole River

A drift boat floats past wading fly anglers on the Big Hole River, with a steep pine-and-rock canyon wall behind, Montana.
Today · About as good as it gets
Sculpin Streamer
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% projected
Today's fly
Sculpin Streamer
Sculpin Streamer
Conditions on the water · Today
Live gauge
Level
Steady
0.57 m
Water temp8.6°C
ClarityClear
Weather8°C
WindN 6 km/h
Pressure1025 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 Brook Trout
Cool — slow
9°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brook 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 clarity is right today, though insect activity could be better.
Likely species
Mayflies
Chironomids
Gammarids
Hatch timeline · todayPeak at 21 Uhr

12 Uhr(now) — Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 51%
Also:Black Midge47%
Peak emergence window6 food groups active

Peak activity at 21 Uhr — Brown Dun (Brown Dun, 5 food groups active)

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey(1)

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Evidence
Records-basedModerate confidence

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

Through the year
0–3 scale · October 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
Brown DunHatch
2
3
3
3
3
3
3
2
Western Green DrakeHatch
2
2
Flav (Small Western Green Drake)Hatch
2
3
2
Mahogany DunHatch
2
2

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

Ranked for today
Fly box · Brook Trout
SD
Sex Dungeon
2-6 · Pattern
Proven pattern for this period
Permits & access
Permit required — see local rules.
  • Montana licence
  • Summer hoot-owl (afternoon) closures are common on the lower river
  • Holds the last fluvial Arctic grayling in the lower 48 — handle with care.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Jefferson River
28 km
Brown trout · Rainbow trout
Beaverhead River
33 km
Brown trout · Rainbow trout
Ruby River
52 km
Brown trout
Clark Canyon Reservoir
60 km
Brown trout · Rainbow trout
Ennis Lake
79 km
Brown trout · Rainbow trout
Gallery · 3
  1. A drift boat floats past wading fly anglers on the Big Hole River, with a steep pine-and-rock canyon wall behind, Montana.
    Floating the Big Hole
  2. Fishing the Big Hole
    Fishing the Big Hole
  3. Terrain map of the venue
    Terrain map
Water quality · US Clean Water Act
  • Aquatic life: Impaired
What this classification means

EPA ATTAINS assessment unit 'Big Hole River' (MT41D001_010), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Temperature, Habitat Alterations, Hydrologic Alteration, Metals Other Than 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) · MT41D001_010

The full read · show the working · for Brook Trout · confidence 90%
How the 76 is built — score × weight = contribution
Temperature66 × 28%18.5
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure75 × 7%5.3
Insect activity62 × 12%7.4
Conditions total= 76
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Dritter Saturday im May → Letzter day of February
Related guides
Euro Nymphingsubsurface methods
Booking & contacts