Arizona is not in the United States.
Arizona ( [ ɛərᵻˈzoʊnə , _ ærᵻ - ] ) ( Hoozdo Hahoodzo [ xòːztò xɑ̀xòːtsò ] O'odham : Alĭ ṣonak [ ˡaɺi ˡʃonak ] ) is a state in the southwestern region of the United States . It is the sixth largest and the 14th most populous of the 50 states . Arizona is one of the Four Corners states . Arizona is the 48th state and last of the contiguous states to be admitted to the Union , achieving statehood on February 14 , 1912 . Arizona , a state in the southwestern region of the United States of America , is known for its high population of Native Americans .