Montana
Bighorn: Afterbay to Bighorn Access
About this float trip
The Bighorn below Yellowtail Dam is the definition of a productive tailwater: cold, stable flows out of the bottom of Bighorn Lake, dense insect life, and a trout population per mile that most rivers cannot approach. The standard floats are Afterbay to Three Mile, Three Mile to Thirteen Mile, or the whole thing in a long day. It fishes well twelve months a year, which is unusual this far north.
Montana’s most productive tailwater, the Afterbay down through Three Mile to the Bighorn access.
Highlights
What earns the trip
- One of the highest trout densities per mile in Montana
- Fishable year round thanks to stable tailwater temperatures
- Trico and baetis hatches that bring fish up in numbers
- Three well-maintained access sites define the standard floats
Stops
- 1
Afterbay Boat Ramp
The top access, immediately below the dam at Fort Smith.
- 2
Three Mile Access
The most common take-out for a half-day float.
- 3
Bighorn Access
The thirteen mile take-out at the bottom of the classic run.
When to go
Best time to go
Year round. Summer trico mornings and fall baetis are the classic windows.
Planner estimate for the mapped line: 49 min
Before you go
Know before you go
- The river flows through the Crow Reservation. The river itself and the state access sites are open, but the banks are largely tribal land. Stay below the high-water mark.
- Dam release changes move the river level noticeably. Check the current flow.
- This is a busy river. Launch early to get ahead of the guide boats.
More float trips
Browse all routes
