A 300-year dry cycle broke on the Americas which caused famine and hardship on most of the human populations. Many civilizations that flourished from farming and sedentary lifestyles collapsed back into hunter-gatherer societies. Migrations of these desperate people led to conflict, raids, and war that further stressed and scattered the peoples of the Americas.
Ancient Civilizations faded, to be replaced with successors that would become known post-European contact as Pueblos, Caddos, Wichitas, and Jumanos. Newcomers, namely the Apaches and their cousins the Navajo, moved into the region as nomads in pursuit of game, adding additional stresses to the region. As these groups reoriented their relationships within and without, new cultural patterns emerged that overlapped into the historic period.
This period of disruption also led to a vast Uto-Aztecan migration in the 1100s from the legendary land of Teguayo or Azatlán (present-day Sierra Nevadas of California and Northern Arizona), with some of these Indians pushing deep into Mexico to eventually found the Aztec Empire. Others, the Numic Peoples, pushed into regions vacated by other populations, establishing a hunter-gatherer domination over the Great Basin and Rocky Mountains. These were the ancestors of the Utes, Shoshones, and Comanches.