FloatETA estimates how long this float actually takes from live discharge at USGS 13042500 (Henrys Fork nr Island Park), not a guidebook average. At a typical 1,400 cfs, a raft drifts about 3.2 mph here. Higher flow speeds you up; skinny water slows you down. Kayaks run faster than the current, tubes slower. Optional fishing adds 35 minutes per mile.
The Henry's Fork (Box Canyon) listing covers 4 river miles across 1 access-to-access stretch (Class II). Times in the table are typical raft hours at that reference flow. Open the live calculator for today's CFS, sunset take-out, water temperature, and rain/UV at the put-in.
See today's Henry's Fork (Box Canyon) float time
Float stretches on the Henry's Fork (Box Canyon)
| Put-in → take-out | Miles | Difficulty | Typical raft time | Notes |
|---|---|---|---|---|
| Island Park Dam (Box Canyon) → Last Chance | 4 mi | Class II | ~1 hr 15 min | Cold, rocky, and crowded with anglers. Give waders room. Harriman State Park below Last Chance is mostly closed to boats — don't float into the Ranch. |
How we time this river
Speed scales with discharge using hydraulic geometry v ∝ Q0.34, calibrated to this gauge. That is why a 1,000 cfs afternoon is a different day than 3,000 cfs runoff. Always scout, wear a PFD, and check Idaho Fish and Game for closures. Gauge page: USGS 13042500.
Common questions
How long does it take to float Island Park Dam (Box Canyon) to Last Chance on the Henry's Fork (Box Canyon)?
About 1 hr 15 min in a raft at a typical 1400 cfs. Kayaks run a bit faster; tubes run slower. Stopping to fish adds about 35 minutes per mile. Cold, rocky, and crowded with anglers. Give waders room. Harriman State Park below Last Chance is mostly closed to boats — don't float into the Ranch.
What USGS gauge is used for Henry's Fork (Box Canyon) float times?
FloatETA uses USGS gauge 13042500 (Henrys Fork nr Island Park) for live discharge. Speed is scaled from a reference 1400 cfs drift of about 3.2 mph.
Is the Henry's Fork (Box Canyon) a good tube float?
Tubes lag the current (we use a 0.72× speed multiplier). On Class I–II stretches tubes can work at moderate flows; skip high water and always wear a PFD.