These sites were occupied during terminal Pleistocene time, in a vastly different climate system than our familiar Holocene climate. The major rivers in Maine had not yet established their present configurations, and isostatic adjustment of the land was in rapid progress. Maine was covered by remnant ice caps in northern Aroostook County. The landscape was dominated by steppe (prairie grass) vegetation. The climate was markedly arid. This time period would end in a span of fewer than 100 years, with massive faunal extinctions across North America and Eurasia.
The PaleoIndian Period is present in Maine.