The history of North America is the study of the past, particularly the written record, oral histories, and traditions, passed down from generation to generation on the continent in the Earth's northern hemisphere and (chiefly) western hemisphere. The indigenous peoples of North America themselves have many creation myths, by which they assert that they have been present on the land since its creation. One of the oldest cultures, yet found is the Clovis culture of modern New Mexico. A more recent example is the group of related cultures called the Mound builders (e.g. the Fort Walton Culture), found in the Mississippi river valley. They flourished from 3000 BCE to the 1500s CE.