Hoover Wilderness is a protected backcountry area in California on the east side of the central Sierra Nevada, within the Inyo and Humboldt-Toiyabe National Forests and extending north and east of Yosemite National Park. Its protection began in 1931 as a Primitive Area, later changing to a Wild Area in 1956 and then a formal Wilderness Area under the 1964 Wilderness Act, with major boundary expansion in 2009. It contains the headwaters of the Walker River and includes well-known destinations such as Twenty Lakes Basin, Virginia Lakes Basin, Sawtooth Ridge, and Matterhorn Peak. It also served as the setting for a 1976 National Geographic Society children’s book.