Tailwater · Mixed · Wyoming, US

Lewis River

Lewis River Yellowstone NP Wyoming 2024

The Lewis River drains Lewis Lake down toward the Snake in the quiet southern end of Yellowstone, and its claim to fame is the channel between Lewis and Shoshone lakes, where big lake-run browns push up to spawn in the fall and draw anglers willing to wade cold water for a shot at a real fish.

Good · Brook Trout
RS2 · 18-22
Goodlive now
A proper day on the water
Low and clear — careful approach country. Stay small, stay accurate.
90% confidence
What moved it
  • LevelDry recentlyNo gauge reading
  • Water temp7.9°C
  • ClarityClear
Today's fly
RS2
RS218-22
High-confidence seasonal pick
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp7.9°C
ClarityClear
Weather0°C
WindSW 8 km/h
Pressure1029 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Brook Trout
Cool — slow
8°C est.ideal 10–16°C
0°14°28°

A dam sets this river's temperature, not the weather, so it can shift several degrees within hours when the release changes. It also warms as it runs away from the dam.

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 time of day could be better.
Likely species
Hatch timeline · todayPeak at 10am

Hatch predictions

Today's headline hatch shown — see all 4 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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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
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2
TricoHatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2

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

Ranked for today
Brook Trout fly box
Permits & access
Permit required — see local rules.
  • Yellowstone NP licence and special regulations
  • Handle spawning browns minimally — the fall run is the headline.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
  1. Lewis River Yellowstone NP Wyoming 2024
  2. Terrain map of the venue
    Terrain map
About this water

The Lewis River drains Lewis Lake down toward the Snake in the quiet southern end of Yellowstone, and its claim to fame is the channel between Lewis and Shoshone lakes, where big lake-run browns push up to spawn in the fall and draw anglers willing to wade cold water for a shot at a real fish. The river proper has meadow and canyon reaches with browns and brook trout. It's lake-fed water, so it runs clear and steady rather than flashing with the weather. Handle the spawning browns with the respect a spawning fish deserves.

  • Mixed
The full read · show the working · for Brook Trout · confidence 90%
How the 76 is built — score × weight = contribution
Temperature70 × 28%19.6
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure75 × 7%5.3
Insect activity75 × 12%9.0
Conditions total= 76
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • Trout Saturday of Memorial Day weekend → First Sunday in November
Related guides
Booking & contacts