Idaho ·
South Fork Snake River Fly Fishing Report - June 7, 2026
SOUTH FORK SNAKE RIVER
ReportJUN 8 — 15, 2026
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Flow
13000CFS
SNAKE RIVER NR HEISE ID
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Water Temp
—
Updated 2026-06-07
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Weather
42–72°F
Mostly Cloudy
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Clarity
Clear
Check post-storm
The South Fork is running 13,000 cfs at Heise (gauge height 5.94 ft) — stable and trending down from the 2026 peak, with exceptional clarity for peak runoff. Water temps are hovering near 48°F, keeping fish tight to slower water and demanding deliberate, slow presentations.
What's Working — Hot Flies
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Salmonfly (Pteronarcys californica) | #4–6 | Building — hatch tracking 7–10 days out; nymphs active subsurface now | Midday through afternoon once hatch arrives |
| Blue-Winged Olive (Baetis spp.) | #18–22 | Active — firing well on overcast days | 10am–2pm on cloudy days (Monday ideal) |
| Caddis (Brachycentrus / Hydropsyche) | #16–20 | Emerging — sporadic afternoon activity | 2pm–dusk |
| Midge (Chironomidae) | #20–22 | Consistent — reliable all day in slower seams and eddies | Morning and evening |
| Pale Morning Dun (Ephemerella spp.) | #16–18 | Early season — beginning to show mid-river; will intensify mid-June | 10am–1pm |
Best Time Window
- Monday 10am–3pm — overcast skies trigger BWO dry fly action; warmest water temps of the day activate nymph feeding in slower seams
- Monday afternoon 2pm–dusk — sporadic caddis emergence; swing soft-hackles and CDC caddis through tailouts before rain arrives overnight
- Tuesday morning before 10am — fish hard before SW winds (17–26 mph gusts to 43 mph) and storm activity shut down surface feeding; nymph deep buckets early
Guide's Tip
From the benchAt 13,000 cfs the South Fork is a drift-boat-only fishery — wading is not safe. Concentrate every cast on the slower water types: buckets behind boulders, tailouts, deep holes, and inside seams where cold-water trout are conserving energy. Water temps at 48°F mean the warmest window of the day (roughly 11am–3pm) is your prime feeding period, so sleep in and fish hard through the afternoon. Monday's overcast skies are a gift — have a second rod rigged with the Parachute BWO ready to deploy the moment you see noses in the film, and keep your nymph rig anchored deep the rest of the time.
Main Species
Yellowstone Cutthroat Trout
Brown Trout
Rainbow Trout
