Sierra National Forest, National forest on Sierra Nevada western slope in California, United States.

Sierra National Forest covers more than 1,300,000 acres on the western slope of the central Sierra Nevada, from oak-covered foothills at about 900 feet up to 13,986-foot peaks. Its terrain rises through forested middle slopes to High Sierra tundra, and the photograph shows a pale gray rocky crest above dark conifer slopes, with a deep blue lake at the base.

The forest was established as Sierra Forest Reserve in 1893 under President Benjamin Harrison as an early protected forest in California. This creation marked an important step in preserving the state's mountain wilderness.

Archaeological discoveries within the forest reveal a 10,000-year presence of Southern Sierra Miwok, Chukchansi Yokuts, and Western Mono indigenous peoples.

Sierra National Forest is divided into three ranger districts: Bass Lake, High Sierra and the Supervisor's Office unit. District offices sit in North Fork and Prather, with the supervisor's office in Clovis and visitor information stations near Mono Hot Springs, at Huntington Lake and on Dinkey Creek Road. The Bass Lake district holds 36 campsites and 17 picnic sites; the High Sierra district has 30 campsites and 11 picnic sites.

The first timber sale on a California national forest took place here in 1899, handled by the United States General Land Office. The forest also holds artifacts dating back over 10,000 years, left mainly by indigenous peoples before written records began about 150 years ago.