The Paleoindian period refers to late-Pleistocene and early Holocene occupations in North America, and encompasses the Clovis, Folsom, Agate Basin, and Cody cultures.

Clovis dates to about 11,500 -10,900 radiocarbon years BP, or about 13,325 – 12,975 calendar years ago.  During this period, the northern latitudes of North America were covered with vast sheets of ice, and the Southwest was a mosaic of pine woodlands and desert scrub. Clovis period people hunted large mammals, including the mammoth, with the distinctive stone point known as the Clovis point.  Clovis sites in the Southwest are famous for megafaunal remains, and include Lehner, Naco, Escapule, and Murray Springs in Arizona, and Mockingbird Gap in New Mexico.  More recent discoveries in Texas, however, attest to both Pre-Clovis people, and to Clovis lifestyles both less mobile and less megafauna-dependant than previously thought.  

Later period Paleoindian cultures are poorly represented in the Southwest, with site concentrations located further east on the Plains.  These cultures were primarily bison hunters, and include Folsom (10,900 – 10,200 radiocarbon years BP) and the Agate Basin/Cody Complex (10,500 to 8,000 radiocarbon years BP).