Cahokia Mounds, approximately 85 Native American earthworks in Cahokia Mounds State Historic Site, SW Ill., near East St. Louis; largest group of mounds N of Mexico. Monks' Mound, a rectangular, flat-topped earthwork, 100 ft (30.5 m) high with a 17-acre (6.9-hectare) base, is named for Trappist monks who settled there in the early 19th cent. The people who constructed the mounds were village dwellers who lived in a fertile river-bottom area; their culture flourished from c.1300 to c.1700. The mounds constitute a national historic landmark.
American Indian Archaeological Sites - The American Indian archaeological record is one of the richest in the world. There are tens of thousands of American Indian sites in the Southwest alone, where the dry climate has preserved a remarkable range of evidence.