Tailwater · Mixed · Wyoming, US

Lewis River

Lewis River terrain map

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.

Today · About as good as it gets
Czech Nymph
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
Czech Nymph
Czech Nymph
Conditions on the water · Today
Estimate
Level
Dry recently
No gauge reading
Water temp11.5°C
ClarityClearing
Weather11°C
WindN 11 km/h
Pressure1013 hPa
Rain · recent1.1 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Ideal
12°C est.ideal 1016°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
Excellent — water temperature is right today, though insect activity could be better.
Likely species
Hatch timeline · todayPeak at 11am

12pm(now) Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Black Midge44%
Peak emergence window7 food groups active

Peak activity at 11am — Western Blue-Winged Olive (Western Blue-Winged Olive, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 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
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
Brown 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
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 Brown Trout · confidence 90%
How the 84 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 84
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Seasons & zones
  • Trout Saturday of Memorial Day weekendFirst Sunday in November
Related guides
Booking & contacts