Waters · United States
South Fork Snake River (Irwin) fishing report
Updated Tuesday, 25 August 2026 · refreshed automatically through the day
Below Palisades Dam the South Fork is one of the last strongholds of native Yellowstone cutthroat, fished from drift boats through a cottonwood canyon. Releases spike hard in irrigation season.
Today's report: fair (46/100)
Rainbow Trout is the most promising species on South Fork Snake River (Irwin) today. Water temperature is around 16.3°C and barometric pressure is stable. Gauge SNAKE RIVER NR IRWIN ID shows the water level falling (1 cm/24h).
South Fork Snake River (Irwin) water temperature and flow
- Discharge: 286.0 m³/s (10,100 cfs) — down 1% over 24 hours
- Level trend: falling (1 cm/24h)
Measured at gauge SNAKE RIVER NR IRWIN ID · reading 52 min ago. Published by the national hydrological service, not estimated by us.
Best time to fish today
- 07:00–09:00 local time — score 47/100
- 10:00–12:00 local time — score 40/100
- 18:00–20:00 local time — score 37/100
3-day outlook by species
| Species | Tuesday 25 Aug | Wednesday 26 Aug | Thursday 27 Aug |
|---|---|---|---|
| Rainbow Trout | 46 — fair | 41 — fair | 40 — poor |
| Brown Trout | 45 — fair | 36 — poor | 38 — poor |
Why this score
Cast & Scan uses a deterministic, published scoring model — no black box. The strongest influences on today's South Fork Snake River (Irwin) rating:
- wind: helping (+1)
- precipitation: helping (+0.9)
- water temperature: helping (+0.88)
- light: helping (+0.85)
- river flow: helping (+0.85)
- pressure trend: helping (+0.8)
Forecast computed Tue, 25 Aug 2026 12:22:18 GMT · data: Open-Meteo + gauge SNAKE RIVER NR IRWIN ID · refreshed automatically through the day · see our published accuracy
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Nearby waters
- Henry's Fork (Lower) — Idaho, USA (76 km away)
- Madison River (Ennis) — Montana, USA (226 km away)
- Wind River (Boysen) — Wyoming, USA (244 km away)
- Green River (Fontenelle) — Wyoming, USA (250 km away)