The settlements at Kodiak Island, Alaska, date from around 4,000 BC when the sea level stabilised. Aleut and Inuit hunters ate mammals and fish. They introduced many tools that improved their marine-based economy. In the north they started hunting caribou. At the same time, hunters built permanent settlement at the Koster site in Illinois and through the Midwest. The Mayan calendar started in 3372 BC in relation to some specific astronomical events but what they were, is unknown to us.
The ancestors of the Inuit moved east up to Greenland around 2,000 BC. They developed the techniques and tools required to survive in their difficult climate. They eventually arrived in subarctic eastern Canada.
Around 825-1000 AD the Athabascan people from Alaska started to migrate into the Pacific Northwest and Southwest following disastrous volcanic activities in Alaska. The Athabascan who moved to Washington State and Vancouver are known as the Pacific Coast Athabascan, the ancestors of the Chasta Costa, Tutuni, Galice, Hupa and Kato. The others moved inland to Arizona and New Mexico where they divided into two groups, the Navajo and the Apache (Jicarilla, Mescalero, Chiricahua and Western Apache). They are known as the Southwestern Athabascan or Apache people; they settled in areas close to the Anasazi.