(From my Fall 2015 Anthropology mid-term exam.)
An ethnography is a description of the customs of different people and their culture. In looking at the history of Alaska Natives archaeology is an important part of building an ethnography because there are no written records to give us descriptions of life in Alaska hundreds and thousands of years ago. Discovering artifacts and features through archaeology (combined with educated guessing, verbal histories, etc.) helps us understand what life may have been like for the first people to arrive in Alaska.
Most theories say Alaska was settled between 50,000 and 15,000 years ago when seas were lower and an arctic grassland (Beringia) stretched between Siberia and Alaska. The first migration probably consisted of hunters following mammoth, bison, and other large animals. A site north of the Brooks Range (in use 12,000 years ago) has produced what appear to be chipped spear points, and microblades and arrowheads (dated to more than 11,500 years ago) have been found in the Tanana Valley.
While nobody knows exactly how natives in Alaska made their way south (boats along the coast or ice free corridors through the glaciers?) there is DNA proof that it happened. There are pockets of Indians down the western coast of the US and into Arizona who share DNA with Alaska natives. Couple that with the archaeological finds and it’s apparent that the Americas were populated by the people who first came from Siberia, across Beringia, into Alaska.