Freestone · Mixed · Wyoming, US

Gibbon River

The Gibbon River meandering through a grassy meadow in Yellowstone National Park, Wyoming

The Gibbon is a small Park meadow river that helps make the Madison where it joins the Firehole, and it's two rivers in one — slow, brushy meadow water full of small browns, rainbows, and brook trout up top, then a tumbling canyon stretch below Gibbon Falls.

Tomorrow · A proper day on the water
Sculpin Streamer
Forecast · Tomorrow
A proper day on the water
A proper day for it. Work the seams with an upstream nymph, switch to the dry when they show.
75% projected
Today's fly
Sculpin Streamer
Sculpin Streamer
Conditions on the water · Tomorrow
Live gauge
Level
Steady
1.44 m
Water temp8.2°C
ClarityClear
Weather9°C
WindN 17 km/h
Pressure1014 hPa
Rain · recent0.1 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 Brown Trout
Cool — slow
8°C est.ideal 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
Water at 19°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Mayflies
Caddisflies
terrestrials
Hatch timeline · tomorrowPeak at 10am

12pm(now) — Black Midge

Stage: On emergersApproach: Emerger or dryActivity: 62%
Also:Mahogany Dun53%
Peak emergence window5 food groups active

Peak activity at 10am — Black Midge (Black Midge, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read 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
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.
  • Yellowstone NP licence and special regulations
  • Geothermal warming on the meadows — leave warm water alone in high summer.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 2
Water here at 19.0°C — the fishing's alive, but these are cooler if you'd rather rest the warm water.
Gardner River
24 km
~9°C
Cutthroat trout · Brown trout · Rainbow trout
Firehole River
28 km
~9°C
Brown trout · Rainbow trout
Gallery · 2
  1. The Gibbon River meandering through a grassy meadow in Yellowstone National Park, Wyoming
    The Gibbon River, Yellowstone National Park
  2. Terrain map of the venue
    Terrain map
About this water

The Gibbon is a small Park meadow river that helps make the Madison where it joins the Firehole, and it's two rivers in one — slow, brushy meadow water full of small browns, rainbows, and brook trout up top, then a tumbling canyon stretch below Gibbon Falls. There's some geothermal warmth in it, so it has the same summer caveat as the Firehole: when the water's warm, leave the fish be. In the cool months a soft-hackle swung through the meadow runs or an attractor in the canyon is honest, low-pressure fun.

  • Mixed
The full read · show the working · for Brown Trout · confidence 80%
How the 34 is built — score × weight = contribution
Temperature24 × 28%6.7
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity46 × 12%5.5
Limiting factor: Water temperature (19°C) is outside Brown Trout's preferred range (10–16°C)= 60
Can you trust it?
Water temperaturelive gauge readinggauge
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.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Saturday of Memorial Day weekend → First Sunday in November
Related guides
Euro Nymphingsubsurface methods
Booking & contacts