east-fork-big-lost

East Fork Big Lost is a stretch on Big Lost River, Idaho.

Also called East Fork of the Big Lost and East Fork of the Lost River.

It is fishable.

Drains the south of the Big Lost basin and joins the North Fork to form the main river. Greg Loomis (Flywaters, Sun Valley guide) calls it by far the best fly water in the upper watershed, a wild-trout stream with limited access across private land. IDFG Fishing Planner: East Fork Big Lost River, a tributary of the Big Lost, 27.9 mi.

It is upstream of Big Lost River Main Stem.

Sourced from 3 sites.

Sources: flywaters.com (retrieved 2026-10-29), Idaho Department of Fish and Game (retrieved 2026-10-29) and The Perfect Fly Store.

Access, closures and rules change; check with the state agency before you go.