The State of Arizona is a state located in the southwestern region of the United States of America. The capital and largest city is Phoenix. The three next largest cities are Tucson, Mesa and Glendale. Arizona was the 48th and last of the contiguous states admitted to the Union on February 14, 1912. Arizona is noted for its desert climate, exceptionally hot summers and mild winters, but the high country in the north features pine forests and mountain ranges which contrast with the lower deserts.