The first people to discover the area arrived over 15,000 years ago. These nomadic hunters settled into distinct cultures about AD 200-500. They were the Hohokam in the south deserts, Mogollon in the east uplands and the Anasazi in the north. They left mysteriously sometime between 1100 and 1540, when the Spanish explorers arrived. Navajo and Hopi also arrived in this period. Athabaskan-speaking people migrated to the Arizona-New Mexico region between 1300 and 1500 and some became classified as Navajo and Apache.