The exact date and route the first humans arrived in North America is still very much a topic of debate. Rapid climate change in the end of the Pleistocene epoch led to glacial receding and rapid sea level rise, making evidence for a coastal-route-hypothesis difficult to obtain. Archaeological sites place people in the Western Hemisphere most certainly by 11,500 years ago; moving across Beringia from Siberia to Alaska. The First Ancestors of the indigenous people of the Americas are considered Opportunistic Foragers and a specialized hunter gathering society. They likely lived in very small-nomadic bands and had little material possessions to leave behind. The Nenana and Denali archaeological cultural sites provides early evidence of early human occupation with lithic stone tools; such as the Microblades tradition.
The end of the Pleistocene and the beginning of the Holocene is defined by dramatic warming and an end to the last ice age. The decline of the Laurentide ice sheet and warmer climate allowed new access for people and animals to move from Asia and into North America. The method and route by which the First Ancestors entered the Western Hemisphere could add valuable insight into the type of society they had. For instance, if they followed a seafaring route along the Coast of Beringia and into North America, the technology and resources involved with watercraft would indicate a different economy than if they followed Refugia animal-herds by foot. However, because of "rising seas, coastal erosion and dramatic coastal landscape changes that have occurred since the end of the LGM, proving that such a migration took place will be extremely challenging" (Erlandson 170). The first people to migrate to the Western Hemisphere certainly lived in small-societal bands, which were likely egalitarian, and characterized by an Opportunistic Forager economy.
The Nenana and Denali complex’s' of central Alaska are believed to be associated with some of the earliest evidence of human habitation in North America. Hoffecker describes the Nenana River valley as "located in the northern foothills of the Alaska Range, containing a group of sites that collectively spans 11,300 to 7000 B.P., and provides critical information on the settlement of Alaska during this interval." (Hoffecker 139). The Denali complex (dated after the Nenana) is often affiliated with the Microblade tradition. Dumond suggests the "Microblade technology appears to be a major thread tying earliest Alaska to Asia" (198). The lithic tradition adds evidence to the First Ancestors way of life and technology with "assemblages including wedge-shaped microcones and microblades, burins of specialized form, various scraping tools, and some bifaces including a few lanceolate points" (Dumond 197). The Microblade traditions multi-purpose tools were used in both hunting and likely gathering and collecting resources. Graf and Bigelow suggest that early Holocene Alaskan “winter hunters occupied lowlands, procuring small game. In late spring and summer when lithic resources were abundant hunters used bifacial implements to pursue large game near major waterways” (448). The tools allowed for survival in a rapidly changing and harsh environment the First Ancestors would have encountered. The first Ancestors were not static however, they changed and adapted to their environment as “hunters