Unequivocal evidence for widespread human settlement in North America dates to c. 13,000 cal bp (all dates herein are in calendar years before present unless explicitly noted), and sites are recognised by the presence of bifacial fluted Clovis-style projectile points, named after a town in eastern New Mexico where they were found in stratigraphic complex in the 1930s and after at the nearby site of Blackwater Draw (Boldurian & Cotter 1999) (Map 2.15.1). The ensuing 10,000 years of human occupation in North America, during the temporal interval from c. 13,000 to 3200 cal bp or c. 11,200–3000 14C yr bp, corresponds to what were traditionally known as the Paleoindian and Archaic stages of cultural development across much of the continent, prior to the appearance of agriculture, monumental architecture and pottery in many areas (e.g., Willey & Phillips 1958; Griffin 1967). All of these cultural developments are now known to have begun much earlier, well back into the Archaic; the date of their appearance varies from area to area if they occurred at all, and the cultures that were present at any given time were highly varied, rendering the use of stage terminology as a marker of cultural development untenable in most areas. For the purposes of the present discussion, and employing usage common in many areas, particularly in the eastern part of the continent, the Paleoindian Period here refers to the interval from c. 13,200 to 11,450 cal bp, or 11,200 to 10,000 14C yr bp, the Terminal Pleistocene geochronological epoch, during the warmer Allerød and the colder and more variable Younger Dryas Period, which occurred from c. 12,850 to 11,650 cal bp (Fiedel 1999; Hughen et al. 2000) (Fig. 2.15.1).