A publication of the Archaeological Institute of America
Watson Brake, in the floodplain of the Ouachita River near Monroe in northern Louisiana, may be the oldest large-scale mound site in the Americas. It has been dated to 5400 B.P. (years before present), making it 1,900 years older than Poverty Point, a ceremonial and trading center in Louisiana which has been dated to 3500 B.P. and was long thought to be the earliest such site.
Consisting of at least 11 mounds from three to 25 feet tall connected by ridges to form an oval 853 feet across, Watson Brake was discovered by Reca Bamburg Jones, a local resident, more than 30 years ago after a timbering operation cleared the land. In addition to radiocarbon testing, the University of Texas at Austin and the University of Washington dated the mound from organic acids and sand grains in the soil.
The new investigation, led by Joe W. Saunders of Northeast Louisiana University, indicates that Watson Brake may have been used as a base by mobile hunter-gatherers from summer through fall. Located above wetlands, the site would have provided access to vast aquatic resources during certain seasons. Bones of the freshwater drum, a species of fish that spawns from spring to early summer, and charred seeds of plants that ripen in the summer and fall were recovered at the site. The findings contradict the commonly held belief that major building projects took place only in complex societies with permanent villages supported by agriculture or trade. Mobile hunter-gatherers, it was thought, were unable to undertake such projects.
The inhabitants of Poverty Point, while not yet agriculturalists, had a complex social organization, took part in extensive trading networks, and possibly maintained year-round occupation. There is no evidence of permanent occupation at Watson Brake, and its few beads, stone tools, and fired earthen blocks were made from local materials, indicating that it did not take part in trade.
The surfaces of the ridges and mounds show little evidence of occupation, leading archaeologists to believe that Watson Brake was occupied primarily before and during the building of the mounds. It is thought that the site was abandoned about 4,800 years ago after the Arkansas River changed course, drying up swamp and small-stream habitats, making the site less suitable for seasonal habitation by hunter-gatherers. Though the purpose of the mounds is unknown, it seems they were not used for burial or religious purposes, as no human remains or ceremonial objects have been found.
The southern half of the site is owned by the Archaeological Conservancy, while the rest is privately owned.