Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of Alta California in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase.
Nevada is largely desert and semi-arid, much of it within the Great Basin. Areas south of the Great Basin are within the Mojave Desert, while Lake Tahoe and the Sierra Nevada lie on the western edge. About 86% of the state's land is managed by various jurisdictions of the U.S. federal government, both civilian and military.