Freestone · Mixed · Montana, US

Gallatin River

A wide, clear bend of the Gallatin River lined with pine trees and mountains in Montana.

The Gallatin is a walk-and-wade freestone that pours out of Yellowstone NP and tumbles down through the canyon — pocket water you fish on foot, the way it ought to be.

Good · Brown Trout
Parachute Adams · 16-20
Goodlive now
A proper day on the water
Low and clear — careful approach country. Stay small, stay accurate.
75% confidence
What moved it
  • Level0.42 mLast reading 2h ago
  • Water temp6.3°C
  • ClarityClear
Today's fly
Parachute Adams
Parachute Adams16-20
Proven pattern for this period
Conditions on the water
Live gauge
Level
Steady
0.42 m
Last reading 2h ago
Water temp6.3°C
ClarityClear
Weather15°C
WindS 12 km/h
Pressure1020 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Cool — slow
6.3°Cideal 10–16°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
Good — water clarity is working for you, but water temperature is the limiting factor today.
Likely species
Mayflies
Chironomids
Gammarids
Hatch timeline · todayPeak at 9pm

Hatch predictions

Today's headline hatch shown — see all 5 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Supporters see what else is on the menu.

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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
Brown Trout fly box
SD
Sex Dungeon
2-6 · Pattern
Proven pattern for this period
Permits & access
Permit required — see local rules.
  • Montana licence
  • No floating on most of the river — it is a wade fishery.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Hyalite Reservoir
31 km
Cutthroat trout · Brook trout
Madison River
38 km
78
Brown trout · Rainbow trout
Yellowstone River
40 km
82
Brown trout · Rainbow trout · Cutthroat trout
Ennis Lake
40 km
Brown trout · Rainbow trout
Quake Lake
48 km
Brown trout · Rainbow trout
Gallery · 2
  1. A wide, clear bend of the Gallatin River lined with pine trees and mountains in Montana.
    The Gallatin River curving through forested valley pastureland in Montana.
  2. Terrain map of the venue
    Terrain map
About this water

The Gallatin is a walk-and-wade freestone that pours out of Yellowstone NP and tumbles down through the canyon — pocket water you fish on foot, the way it ought to be. Rainbows and browns down low, cutthroat up in the headwaters. The salmonflies show in early summer, but only once the river has dropped and cleared off after runoff. Show up too early and you'll just stand in cold mud water and call it scouting.

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

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

EPA ATTAINS assessment unit 'Gallatin River' (MT41H001_021), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Algal Growth. 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) · MT41H001_021

The full read · show the working · for Brown Trout · confidence 75%
How the 68 is built — score × weight = contribution
Temperature39 × 28%10.9
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity53 × 12%6.4
Conditions total= 68
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 Third Saturday of May → Last day of February
Related guides
Euro Nymphingsubsurface methods
Booking & contacts