The century and a half from AD 1250 to AD 1400 saw massive shifts in the distributions of human populations on the Plains, the social groups that they lived in, and the interactions among these groups. These shifted again in the next 100 years, transforming the human landscape of the Plains in just a few generations. We see these changes more precisely in at least some areas because the radiocarbon calibration curve is smooth and straight for the 1400s (Figure 7.8). There seems especially to have been a major shift in settlement in the mid-1400s that corresponded with a dramatic drought (a “megadrought”) extending from the Dakotas into Texas (interestingly, tree-ring data suggest that the Canadian prairies were not affected by this drought, although the later 1400s were relatively dry there; Case and MacDonald 2003; Cook et al. 2007; Stahle et al. 2007). I consider this interval among farmers first and then turn to hunter-gatherers.

By the mid-1200s, a traveler across the Plains would have encountered a wide array of communities and lifeways. In the far southwest, scattered households of small-scale farmers with strong ties to the southern part of the American Southwest lived in much of the Pecos Valley, while similar communities with closer connections to the Taos area lived to the north of them, perhaps into Colorado. People who made brownware pottery like that in the southern Southwest also occupied the grasslands from the Pecos across the southern Llano Estacado and may still have had settlements in the eastern Texas Panhandle and to the edge of central Texas, where they perhaps lacked maize horticulture but retained southwestern ceramic and other traditions. In Texas, these eastern groups would have met aceramic, probably seasonally settled, generalist hunter-gatherers. From Oklahoma to North Dakota, farmers dominated much of the eastern two-thirds or so of the region, living in fairly small communities in more southern areas and in substantial towns with hundreds of inhabitants in the north. All of these farmers grew maize and other cultigens, although they varied widely in their emphasis on this and there were persistent enclaves of communities (in areas like southeastern Kansas and the eastern part of the Dakotas) who knew and interacted with them but whose ways of life had changed relatively little since Late Woodland times. Much of the Western Plains of Colorado and Wyoming seems to have been substantially depopulated at this time, but farmers certainly reached out to the west in ways that we still do not fully understand. And industrial bison hunters filled the grasslands to the north and northwest, as they had for centuries.