The Paleo-Indian ( not so often Lithic ) period or era is that which begins with the first signs of human presence in the region and leads to agriculture and other practices ( e.g. pottery , permanent settlements ) characteristic of proto-civilizations . The Paleo-Indian ( less frequently , Lithic ) period or era is that which spans from the first signs of human presence in the region , to the establishment of agriculture and other practices ( e.g. pottery , permanent settlements ) and subsistence techniques characteristic of proto-civilizations .