According to what is known about the United States before Europeans' immigration, there is no trace of primitive men such as Pithekanthropos, Sinanthropos, or Neanderthal men in the region. Only the human bones almost the same as those of Indians have been found to date. It is speculated that Indians moved from Asia to North America on numerous occasions, thus becoming the first residents on the continent. Many of them first settled in the east but were expelled by Europeans. Some were scattered to the South and the North, while the majority settled in areas covering the Midwest and the Southwest. Part of their culture still remains. The culture developed by them in the Southwest called Anasazi culture. The culture was inherited by the Pueblo culture.

Form around the early 11th century to the latter part of the 13th century, dwellings were built under the overhangs of the cliff. In some cases, more than 500 communal dwellings were built under one cliff and elaborately woven cotton cloths were also found.