The Salmon-Challis National Forest encompasses over 4.3 million acres in central Idaho and includes the Frank Church River of No Return Wilderness Area, the largest contiguous area in the continental United States. Named after the Salmon and Challis Rivers, which run through the diverse landscape of mountains, canyons, alpine expanses, and high desert, the forest delivers outstanding recreational opportunities. You can escape into the backcountry in the Lemhi, Bitterroot, Pioneer, or Lost River Mountain Ranges or venture to the Bighorn Crags within the Frank Church. The forest is also rich in heritage, with historic cabins, ranger stations, lookouts, mining ghost towns, and the Lewis and Clark and the Nez Perce National Historic Trails linking to the past.