EDISTO ISLAND — Two of the coast's mysterious shell rings — human-made and centuries old — lay buried in the woods on tiny Pockoy Island. For years nobody knew they were there.
Now, state and federal archaeologists are digging feverishly to learn what they can before the rings disappear.
As the teams pitched shovels and sifted the dirt on a recent morning, high tide lapped against the silt fence that is all they have left between the first ring and the sea. Pockoy, a slender strip of barrier island at Botany Bay Plantation Wildlife Management Area on Edisto Island, is eroding at a sizable rate of nearly 30 feet per year.
The archaeologists hope they have two more years to work the first ring. They know they might have only until the next storm. When they first staked out the site in 2017, it was back in the trees. Today, piles of its oyster and mussel shells are washing away in the beach surf just over the silt fence.
The rate of erosion is astonishing, said archaeologist Karen Smith, of the South Carolina Heritage Trust.
Shell rings are roughly circular structures created from shell discards by hunter-gatherers about 4,000 years ago. More than 60 have been discovered in the Southeast from the Sewee Mound near Awendaw to Mississippi.
The Pockoy rings, once hidden by an overgrown forest, were found only because a researcher scanning a lidar image of the coast noticed the weird circles. Lidar is like a cross between radar and a CT scan.
Nobody knows just how important a historic and cultural resource shell rings might be.
Of the two rings closest to Pockoy, the Spanish Mound at Edisto Beach State Park is virtually lost to erosion. The remote Fig Island, the largest of the South Carolina rings, is falling in and becoming more difficult to reach.
Native Americans began piling oyster, clam and other shells into the eventual rings during the time of the earliest pyramids. In a relatively few years, they presumably feasted on billions of shellfish and other fish.
These were the Archaic people, until recently the first known people to inhabit South Carolina. They turned up about 12,000 years ago and lasted as a cultural group until agriculture developed about 4,000 years ago.
The rings are thought to have been piled for more than 400 years toward the end of that period.
Then the Archaic virtually vanished, leaving behind few clues as to who they were beyond the rings.
The rings were relatively huge structures, ranging from more than a half a football field wide to nearly three football fields wide. Their walls were piled more than 10 feet high.
The people began to create them at a pivotal point in the culture, the same time they started making pottery, developed tool technology like axes fashioned from sharpened whelks and created craft like tiny bone pins delicately etched with concentric rings and repeating diamond patterns.
"The preconception is 4,000 years ago people were eking out a living," Smith said. But these people had enough leisure time to pursue arty craftwork. "What was life like?"
Their technological advances alone were staggering, said archaeologist Sean Taylor, of the trust. He points out how shells were chipped at and edged to form spear blades, the shafts fitted onto atlatls, or spear throwers, to be flung at game. He also demonstrated how a edged whelk mounted on a stick cuts green wood as cleanly as a steel hatchet.
But the purpose of creating the shell rings continues to puzzle. Why were the interiors off into chambers? Did people live or just feast there? Was their use seasonal or year-round? Why are the rings sometimes found so close to each other, in complexes? Were they constructed at about the same time, or across succeeding generations?
The Pockoy discovery team hopes at least to get a better bead on the chronology.
The investigation is also considered a large one for a dig site — a dozen archaeologists supported by a National Park Service surveying crew and rotating volunteers from schools in the region. As digs go, they know that investigating shell rings are time and labor intensive and calendar sensitive.
"We get a hurricane this year, or even a bad northeast wind with a king tide, and this is going to be gone," Taylor said.