The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages 193 million acres (780,000 km2) of land. Major divisions of the agency include the Chief's Office, National Forest System, State and Private Forestry, Business Operations, and Research and Development. The agency manages about 25% of federal lands and is the only major national land management agency not part of the U.S. Department of the Interior, which manages the National Park Service, the U.S. Fish and Wildlife Service, and the Bureau of Land Management.