The remains of Archaic cultures, especially those dating 8,000 to 4,000 B.P., are not well documented in the archaeological record of the Central Plains of the United States. Some researchers have suggested that people abandoned the region during this period because of increased aridity and associated displacement of game. However, there is strong evidence that geomorphic processes, particularly erosion and deposition, have greatly affected the preservation and detection of Archaic and younger cultural deposits.

Chronostratigraphic evidence gleaned from more than 65 localities reveals spatial and temporal patterns of Holocene erosion and deposition in river basins of the Central Plains. Both...