Henry's Fork
HENRY'S FORK
ReportDry-dropper rigs, large nymph and terrestrial insect patterns fished close to banks are standard for fishing Box Canyon. Overcast conditions offer the best fishing, with early mornings having BWOs emerging throughout the river. Terrestrial insect patterns dead-drifted in front of banks before the bright midday sun arrives bring trout up everywhere. Stealth, long fine leaders, and precise casts are the name of the game.
Please play any trout no longer than necessary and do all you can to revive it enough to swim away on release. We want those big guys back in the gene pool!
From Warm River downstream, summer heat makes early and late in the day the best time to fish. PMDs are becoming much less numerous as summer rolls on, but late in the day caddis activity brings fish up. Take a break during midday and maybe until evening as the river is warmest in the afternoon.
Flow at Box Canyon is about 770 cfs, below Ashton Dam is about 1,820 cfs, and about 1,370 cfs at St. Anthony.
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Blue-Winged Olive (BWO) | #20-22 | Moderate — best on overcast mornings | Early AM |
| Terrestrials (Hoppers & Ants) | #12-16 | Strong — dead-drift tight to banks | Morning to pre-midday |
| PMD (Pale Morning Dun) | #18-20 | Declining — less numerous as summer progresses | Morning |
| Caddis | #18-20 | Good — evening activity bringing fish up | Late afternoon to dusk |
- EARLY MORNING (first light to ~10 AM): Fish BWO hatches throughout Box Canyon and dead-drift terrestrials tight to banks before the bright midday sun arrives
- EVENING (late afternoon to dusk): Prime window below Warm River for caddis-driven surface activity; skip the warm midday hours entirely
