Paleoindians were well-adapted, highly mobile communal bison hunters who possessed sophisticated stone tool hunting technologies and had developed widespread trade networks. The major elements they lacked relative to later Classic bison hunters are the massive jumps, associated processing camps, bone grease extraction and pemmican processing technology, and the skin-covered tipi. It is during the Early Prehistoric or Paleoindian Period that the first certain associations of stone-tipped weapon points and bison kills are known. Pemmican consists of pounded dried meat mixed with fat and berries placed in skin bags along with liquid bone grease. Pemmican technology, as represented in archaeological sites by rocks fractured during stone boiling, bone boiling pits, extensively smashed selected bones, and bone spill piles, first appears in sites on the Northern Plains. In Pemmican the most intensive phase, was triggered by the incorporation of the bow and arrow into their technological system.