Hunter-gatherer lifeways continue in the Eastern Woodlands, where peoples of the Adena culture build earthworks at floodplain locations along the Ohio River valley, and develop complex communal ceremonies. Burial customs are elaborated: grave goods include luxury materials and personal ornaments as well as tools. In the Southwest, while population mobility is still a factor, shallow pithouses are constructed. Pottery use is initiated. The Arctic peoples around the Bering Strait develop a successful marine hunting technology, probably based on Asiatic traditions, for the capture of sea mammals. Objects associated with hunting and burial are carefully made and decorated, implying ritual significance.
ca. 800 B.C. Adena peoples erect earthworks and mounds in present-day Ohio, Indiana, Kentucky, West Virginia, and Pennsylvania.
ca. 500 B.C. The Old Bering Sea culture, heavily dependent on sea resources, begins to coalesce around the Bering Strait between Alaska and Siberia.
ca. 200 B.C. Archaic cultures wane in the Southwest; plain brown pottery is in use.
ca. 100 B.C. Walrus ivory is carved into Okvik figures, other ornaments, and implements on the St. Lawrence and Punuk islands in the Bering Strait; semi-subterranean houses are built.
ca. 1 A.D. Caches including duck decoys made of tule reed are placed in Lovelock Cave, Nevada.