The Gila National Forest is a protected national forest in New Mexico in the southwestern United States established in 1905. It covers approximately 3.3 million acres (5150 sq. mi., 13,000 km²) of public land, making it the sixth largest National Forest in the continental United States. Part of the area, the Gila Wilderness, was established in 1924 as the first designated wilderness by the U.S. federal government. Aldo Leopold Wilderness and Blue Range Wilderness are also found within its borders. The forest lies in southern Catron, northern Grant, western Sierra, and extreme northeastern Hidalgo counties in southwestern New Mexico. Forest headquarters are located in Silver City, New Mexico. There are local ranger district offices in Glenwood, Mimbres, Quemado, Reserve, Silver City, and Truth or Consequences.