An overview and model of complex society in the prehistoric Southeast. Along the banks of the lower Chattahoochee River, the remains of ancient settlements are abundant, including archaeological sites produced by Native Americans between 900 and 350 years ago, and marked by the presence of large earthen mounds. Like similar monuments elsewhere in the Southeastern United States, the lower Chatta-hoochee River mounds have long attracted the attention of travelers, antiquarians, and archaeologists.