Freestone · Mixed · Wyoming

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.

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
  • Level1.52 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
1.52 m
Dropping after lift
Water temp19.3°C
ClarityClear
Weather9°C
WindE 4 km/h
Pressure1020 hPa
Rain · recent4.7 mm
Rain · ahead0.6 mm

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

Water temperature for Brown Trout
Warm — slow
19.3°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
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

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Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

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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
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.
  • 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
Water here at 19.3°C. Nothing cooler within range.
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 32 is built — score × weight = contribution
Temperature35 × 28%9.8
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity48 × 12%5.8
Conditions total= 64
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
  • TroutSaturday of Memorial Day weekend → First Sunday in November
Related guides
Euro Nymphingsubsurface methods
Booking & contacts