Pick your float
Choose a state, a river, and your craft. We pull the latest gauge reading and estimate your time on the water.
Float times are estimates based on current gauge flow and typical drift speeds. Mileages are approximate. Conditions change fast — always scout, wear a PFD, and check MT FWP or Idaho Fish and Game for closures.
River reports
Strainers, fences, diversion dams — if you saw it, report it. Help the next boat down.
Latest reports
Reports retire automatically after 45 days unless someone taps “Still there” — so what you see here is current, not last spring's news.
How the math works
Live gauge data
Every river here is tied to a USGS streamgage. We pull the instantaneous discharge (cfs) and water temperature, refreshed every time you load the page.
Flow → speed
River speed rises with discharge. We calibrate each river's typical drift speed at a reference flow, then scale it using the hydraulic-geometry relationship v ∝ Q0.34.
Your craft matters
A paddled kayak outruns the current; a tube with a cooler lags behind it. We adjust the estimate for what you're actually floating in.
Beat the sunset
We compute sunset at the put-in and tell you the latest reasonable launch time, so you're not navigating strainers in the dark.
Popular Montana floats
Every river has its own page with stretches, typical raft times, and the USGS gauge we use. The calculator above uses today's CFS.
- Madison River (Upper)Lyons Bridge to Ennis
- Madison River (Lower)Bear Trap and Black's Ford
- Yellowstone (Paradise Valley)Emigrant to Springdale
- Gallatin River (Canyon)House Rock and the Mad Mile
- Blackfoot RiverRussell Gates to Bonner
- Clark Fork (Missoula)Downtown past Brennan's Wave
- Bitterroot (Stevensville)Bell Crossing to Buckhouse
- Big Hole RiverDivide to Notch Bottom
- Missouri River (Craig)Holter Dam tailwater
- Smith RiverPermit lottery, 59 canyon miles
- Alberton GorgeWestern Montana whitewater
- North Fork FlatheadPolebridge to Glacier Rim
Popular Idaho floats
Same live-CFS calculator, now on the Greenbelt, the South Fork Snake, Henry's Fork, and Payette whitewater.
- Boise River (Greenbelt)Barber Park to Ann Morrison
- South Fork Snake (Canyon)Conant to Byington
- Henry's Fork (Box Canyon)Island Park Dam to Last Chance
- Payette River (Banks)Banks to Horseshoe Bend
- Salmon River (Riggins)Town floats and Lower Salmon
- Lochsa RiverHighway 12 spring whitewater
- Clearwater RiverOrofino to Spalding
- St. Joe RiverAvery to St. Maries
Float-time questions
Short answers to what people ask before they put in.
How long does it take to float a river in Montana or Idaho?
It depends on today's flow, the stretch, and your craft. A 9-mile Class I run might be 2.5 hours in a raft at a healthy cfs and closer to 4 hours on a tube or if you stop to fish. FloatETA converts live USGS discharge into an ETA for each listed stretch.
How does FloatETA calculate float time?
Each river is tied to a USGS streamgage. We take a typical raft drift speed at a reference flow, then scale it with hydraulic geometry (speed rises with discharge to the 0.34 power). Kayaks, tubes, and paddleboards get their own multipliers. Optional fishing adds 35 minutes per mile.
What CFS is good for floating?
There is no single good number. A river looks Prime near its reference flow, bony well below it, and pushy well above it. Use the condition badge on each river: Low & bony, Mellow, Prime, High & fast, or Runoff.
How much extra time if I stop to fish?
Turn on Stopping to fish and we add 35 minutes per mile on top of drift time. A 9-mile stretch gains about 5 hours 15 minutes.
Which rivers does FloatETA cover?
Montana and Idaho. Montana includes the Madison, Yellowstone, Gallatin, Big Hole, Blackfoot, Clark Fork, Bitterroot, and more. Idaho includes the Boise Greenbelt, South Fork Snake, Henry's Fork, Payette, Salmon, Lochsa, Clearwater, and St. Joe. Directories: Montana and Idaho.
Can I still launch if it is getting late?
The calculator uses sunset at the put-in and tells you the latest reasonable launch, or your take-out time if you enter a put-in. Leave a buffer — strainers after dark are a bad plan.
More states are coming
Montana and Idaho are live. Oregon, Wyoming, and Colorado are next, with the same live-flow float times, daylight planning, and obstruction reports.