Lassen Volcanic National Park covers 165 square miles or about 106,000 acres, located in Lassen, Shasta, Plumas and Tehama counties on the southern edge of the Cascade Range in northern California. Nearly 79,000 acres in the park are designated as wilderness area. Lassen Volcanic National Park receives fewer than 400,000 visitors per year. Cinder Cone National Monument and Lassen Peak National Monument were established by proclamation of Theodore Roosevelt on May 6, 1907 to be administered by the U.S. Forest Service. Volcanic eruptions from Lassen Peak in 1914 and 1915 resulted in national publicity. The two monuments and surrounding areas were included in Lassen Volcanic National Park, established in 1916, administered by the National Park Service of the Department of the Interior.