The Big Lost River flows through central Idaho in the Snake River region. The river is appropriately named as it disappears below ground before reaching the Snake River. It drains beneath the surface right into the Snake River aquifer. Sun Valley, Idaho serves as a base for the river and it’s popular with anglers searching for trout in the area.
Flows And Weather
Rapids and Float Notes
The best of the floating on the Big Lost River in Idaho happens during spring runoff when flows are high on the upper section of river. The East Fork especially is a narrow and fast run with plenty of obstacles for experienced paddlers. Otherwise, the river is primarily suited to wade fishing and hiking.
The area below Mackay Dam is also a controlled release so the flows do not spike like the upper river. This however does make it a viable fishery throughout the entire year.
Shuttle Services
Not being a popular float river means there is a lack of shuttle service on the river. You should consider running your own shuttles to make it work here.
Fishing the Big Lost River
Trout and whitefish are prolific here. The upper section is a freestone fishery with plenty of water to hike and explore while chasing the wild trout. Head to the more popular zone below Mackay Reservoir where the trout can grow a little larger with the tailwater fishery.
The entire valley and river system is incredibly scenic with little in the way of development. It’s a great opportunity to change things up after fishing Silver Creek. The fishing is less technical although the rainbows below the reservoir can get pretty picky at times.
Overall, the river is a bucket list place to visit and fish in Idaho.
