The Navajos moved into Utah and were in the Four Corner area by AD 1400. Although the Navajo, who spoke an Athabaskan language as opposed to Numic, were Numic contemporaries, they weren’t amicable.
The Navajo presently still reside in the southeastern corner of Utah and the Four Corner area. More than half of the population of San Juan County, Utah is Navajo – most living south of the San Juan River.
Because the Navajo archaeology dates to times when there is written documentation about their early practices and ways of life archaeologists consider them in the category of “historic,” and not “prehistoric.”