Salmon–Challis National Forest is located in east central sections of the U.S. state of Idaho.

At 4,235,940 acres (6,618.66 sq mi, or 17,142.24 km2) it is one of the largest national forests in the lower 48 states and also has most of the land area of the Frank Church–River of No Return Wilderness, which is the largest wilderness area south of Alaska.

There are local ranger district offices located in Challis, Clayton, and Mackay.

[1] There are local ranger district offices located in Leadore, North Fork, and Salmon.

There is a weather station at Middle Fork Lodge, which is on the western edge of Salmon–Challis National Forest.