Tailwater · Mixed · Idaho, US

South Fork Snake River

South Fork Snake River fishing venue photo

The South Fork below Palisades is the best big-river cutthroat fishery left in the West, and it's a working drift-boat river — long fertile runs through cottonwood canyon, native Yellowstone cutthroat that eat dries with their whole heart, plus browns and rainbows.

Tomorrow · About as good as it gets
Czech Nymph
Forecast · Tomorrow
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.
75% projected
Today's fly
Czech Nymph
Czech Nymph
Conditions on the water · Tomorrow
Live gauge
Level
Steady
1.32 m
Water temp11.5°C
ClarityClear
Weather16°C
WindN 4 km/h
Pressure1013 hPa
Rain · recent1.8 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
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 time of day could be better.
Likely species
Hatch timeline · tomorrowPeak at 11am

12pm(now) Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 89%
Also:Black Midge53%
Peak emergence windowWeather boost8 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

Top nymph shown — see all 2 guilds with Pro.

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14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 with Pro.

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14-day free trial. Cancel anytime.

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
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
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.
  • Idaho licence
  • Native Yellowstone cutthroat conservation rules apply; rainbow-harvest regulations protect the pure cutthroat — check Idaho Fish & Game
  • Fishability tracks the Palisades release.
What's coming
Plan ahead
5-day outlook
Other water nearby · 2
Gallery · 2
  1. Venue photo
  2. Terrain map of the venue
    Terrain map
About this water

The South Fork below Palisades is the best big-river cutthroat fishery left in the West, and it's a working drift-boat river — long fertile runs through cottonwood canyon, native Yellowstone cutthroat that eat dries with their whole heart, plus browns and rainbows. The salmonfly hatch in June is a circus in the best way. There's a serious conservation story here: rainbows hybridize with the native cutthroat, and Idaho manages hard to protect the pure fish, so respect the rules and treat the cutthroat as the irreplaceable natives they are. Flow comes off the dam, not the sky.

Under the surface

The South Fork of the Snake comes out of Palisades Reservoir and runs through eastern Idaho as the great cutthroat stronghold of the region — a big, braided, cottonwood-bottomed river that carves through a basalt canyon below Conant before spreading into island country on its way to the Henrys Fork. The flow is dam-governed at the top but the river fishes like a freestone, fast and broad over rounded cobble, the side channels and seams holding native Yellowstone cutthroat alongside browns and rainbows. The cottonwood gallery forest along it is the finest left in the West, and in late summer the cutthroat tip up for hoppers along the grassy banks. The bed is volcanic cobble and gravel; the braids make for endless water. Wading is honest freestone work, and the side channels are kinder than the heavy main stem.

Wading: Heavy main stem, kinder side channels

  • Mixed
  • Partly confined
  • Pool riffle
  • Large river
Water quality · US Clean Water Act
  • Aquatic lifeImpaired
What this classification means

EPA ATTAINS assessment unit 'Snake River - Palisades Reservoir Dam to Fall Creek' (ID17040104SK008_06), 2022 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Hydrologic Alteration. 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) · ID17040104SK008_06

The full read · show the working · for Brown Trout · confidence 75%
How the 81 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 81
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 1 January31 December
Related guides
Booking & contacts