Clovis, Sandia, and Folsom points, together with related stone implements, are at many places enclosed in sediments deposited in or adjacent to ponds, lakes, streams, and wet meadows. These environments indicate a former cool and more humid climate in areas that are now semiarid. The food requirements of many of the large herbivores that lived at this time also suggest more abundant vegetation and surface water than prevails here today. It is not unreasonable, then, to presume that climatic conditions contributing to the advance of continental glaciers in the Great Lakes region, and to valley glaciers in the Rocky Mountains, should have been reflected in lower summer temperatures and higher rainfall in non-glaciated areas. The ultimate extinction of the large Pleistocene mammals and the similar time of disappearance of the hunters who preyed upon them may both be related to the climatic changes that followed the end of the Ice Age in America. HUNTERS AND GATHERERS Groups of people dependent upon a different way of life from that of the Early Hunters are known to have occupied much of the present area of New Mexico. Although there is some suggestion of overlap in time of these people with the Early Hunters, they appear to have become prominent during the several thousand warm, dry years following the end of the Pleistocene. Adapted, as they were, to a fuller utilization of the resources of the area through the hunting and trapping of smaller game and an emphasis on the gathering of a wide variety of wild plant foods, these people ranged extensively across the varied terrain of the state. Similar patterns of subsistence and artifacts are known from the Great Basin region west of the Rocky Mountains, where they have been categorized under the term _Desert Culture_. Local manifestations of the Desert Culture in southeastern Arizona, extending eastward into western and southern New Mexico, are identified as the Cochise Culture. Other groups showing similarities with Archaic cultures to the east penetrated the northeastern part of New Mexico at a time when the area was still populated by Pleistocene bison. Habitation sites of these gatherers are distributed in open situations and in shelter caves. Such sites are commonly marked by milling stones that characterize the preparation of wild foods (fig. 3), hearths, chopping and scraping implements, and stemmed projectile points markedly different from those used by the Early Hunters. These points were affixed to dart shafts that were propelled with a spear thrower or _atlatl_, a device that preceded the bow and arrow in America but is still used by Australian Aborigines.