The Indian mounds deep in the northeast corner of Louisiana (U.S.A.) don't look like much. Until a timber company clear-cut the trees and thickets at Watson Brake in 1981, nobody even realized they had been built to create a greater shape. And it took nearly two decades after that to discover that they are the oldest known grouping of mounds in the Western Hemisphere. They might not have survived without Reca Jones, an amateur archaeologist.
      The mounds and their purpose are a mystery, but they have become a touchstone for archaeologists studying the Middle Archaic period, around 6000 BCE to 3000 BCE. "Many people thought the Middle Archaic was people running around doing hunter-gathering things for 3,000 years," said Mark Barnes, a National Park Service archaeologist. "They were much more sophisticated than we thought."
      Jones had known since she was a child that there were old Indian mounds there. Then Willamette Industries Inc., which owned half the site until the Archaeological Conservancy bought it in 1996, cut the trees. Suddenly Jones could see that there were more mounds than she'd realized, with ridges connecting them into a giant egg shape. It was about 300 yards from end to end and 200 yards across.
      "I was here almost the whole time Willamette was here, saying, 'Don't get on the mounds! Don't get on the mounds!'" Jones said. Willamette complied.
      Then she asked a Harvard archaeologist to map the site with her, but it wasn't until July 1993 that Joe W. Saunders, the state's archaeologist for that region, drilled the first sample. Bit by bit, the evidence added up. The find went public last year, in Science magazine.
      Jones' discovery, her years of work to get a professional to excavate it, and her work in the excavation and reconstruction won her the Society of American Archaeologists' Crabtree Award for amateur archaeology.
      Scientists have dated the remains to 5,400 years ago. But many questions may never be answered. For one, why were the mounds built?
      Some of the oldest Indian mounds seem to be trash heaps covered with dirt. Here, sometimes the builders covered an area where they had lived and worked, camped on the new surface, then covered it over again. But others are just dirt on dirt. And all of the work appears to have begun at about the same time.
      About 60 percent of the oval is a natural ridge which once overlooked swamps and a tributary of the Arkansas River. But why build it higher, and why close in the rest? It probably wasn't flood protection; the land already was well above flood level. The oval encloses nearly 22 acres. Subdivisions have been built on less. But there's no sign that anyone lived in most of that space, aside from three small natural rises. "Perhaps we ask the wrong question. Perhaps constructing the mounds was the purpose," Saunders says.
      What can be verified? Bones and shells reveal that the mound builders ate lots of fish, mussels and aquatic snails, and some turtles and small animals. The leftovers also indicate that the people came in the spring and left in the fall.
      Only a few fragments of human bones have been found. But bones found in other areas indicate that the builders were probably about 5 feet 2 inches tall. The smallest mounds were about chest-high to them, the biggest as tall as two-story buildings. Excavation and reconstruction won't be the end of work here.
      The state wants to buy the northern half of the site and establish a state park. The Archaeological Conservancy bought the southern 80 acres from Willamette in 1996, and sold it last year to the state.
      The long-term hope is for a series of sites, one for each period - a prehistoric trail through Louisiana.

Sources: Associated Press, Nando Times (5 December, 1999), The Sun Herald (7 December, 1999)