A Louisiana farm wife's persistence has led to what archaeologists are describing as a major discovery: the oldest known native-American mound "encampment" in North America.
Why the mounds were built remains mystery. But even with that question unanswered, they show that hunter-gatherer cultures of about 5,000 years ago "were capable of undertaking public architecture, an attribute of more complex societies," adds Joe Saunders, lead archaeologist on the project.
Built centuries before Egypt's Pharaohs raised their first pyramid, the 11 mounds at the site in northern Louisiana form an oval enclosure that is 1,900 years older than the next-oldest mound enclosure, also in Louisiana.
The find is also forcing researchers to revise their views about the society that inhabited this region 5,000 to 5,400 years ago.
"This find is extremely significant," says Robert Connelly, an archaeologist at the nearby Poverty Point mound complex, near Epps, La. Not only does it push back moundbuilding dates in North America, he continues, it also lays to rest the notion that Mesoamerican cultures, such as the Olmecs, who thrived in a region near what is now Vera Cruz, Mexico, were the source for monumental architecture in North America. "People in northeast Louisiana were 'doing Olmec' before the Olmecs," he quips.
At the Watson Brake site, 20 miles southwest of Monroe, La., the largest mound stands 7.5 meters (24.6 feet) tall and is a familiar feature to long-time area residents.
"I've lived in Ouachita Parish all my life. Everybody knew about this big mound, and there were little rises," says Reca Jones, the woman researchers credit for bringing the mounds to their attention. But, she adds, no one knew that the mounds and rises formed an oval. In the mid-1970s, after a timber company clear-cut the hardwood stands covering the site, "I walked it and realized, 'Hey, these ridges connect to these mounds.' "
Mrs. Jones, the wife of a retired farmer and an amateur archaeologist, says she tried to interest various professional archaeologists in her discovery. One Harvard University archaeologist went so far as to map the area in 1983. But none took the site on as a major research project. Some dismissed it as part of the Poverty Point culture. Others held that the enclosure was the remains of a Spanish fort.
In 1992, she took her cause to Dr. Saunders, an archaeologist and adjunct faculty member at Northeast Louisiana University in Monroe. The next year, the two began taking core samples from the mounds. The temperature and humidity that July drove the heat index up to a sweltering 112 degrees, recalls Jones, noting that for the first two summers she and Saunders were the only two people working the site.
Now the research team has 15 members, including biologists, paleontologists, physicists, soil scientists, and archaeologists. To zero in on the age of the Watson Brake mounds, the team used several techniques - all pointing to construction sometime between 3,000 and 3,400 BC.
THE society that built the compound consisted of hunter-gatherers, notes Edwin Jackson, an anthropologist at the University of Southern Mississippi in Hattiesburg and a member of the research team. Built on a forest-floor terrace overlooking the Ouachita River, the site was occupied seasonally, rather than year-round.
Analyzing more than 175,000 pieces of animal bone researchers found at the site, the team concluded the occupants' diet consisted mostly of fish and fresh-water mussels, augmented by deer, turkey, squirrels, and other wildlife. Other artifacts include blades, drills for beadmaking, and undecorated chunks of fired earthen objects in a variety of shapes.
Although researchers see no evidence of agriculture, they have found tantalizing hints that during the 1,900 years that elapsed between Watson Brake's construction and the rise of the Poverty Point culture, the inhabitants of northeastern Louisiana may have begun to domesticate wild plants, perhaps in small gardens.
Until archaeologists pinned down Watson Brake's age, Poverty Point was the oldest mound complex, so much older than any other that it was seen as a fluke.
"We thought Poverty Point, with its geometric mounds and fine lapidary work, was precocious, a bit like the Emerald City of Oz appearing in a desert," says George Stuart, vice president for research and exploration at the National Geographic Society in Washington. "With Watson Brake, we are getting a glimpse of what might be the roots of Poverty Point."