A Stone Pyramid At Cahokia, Illinois?

St. Louis Post-Dispatch

Archaeologists have made an astonishing discovery at the Cahokia Mounds State Historic Site: what appears to be a large stone structure beneath the site's biggest earthen mound.

The site was discovered accidentally Jan. 24 during drilling to construct a water-drainage system within Monks Mound, the largest Indian mound north of Mexico and the largest prehistoric earthen construction in the New World.

"This is astounding," said William Woods, an archaeologist with Southern Illinois University at Edwardsville, who is leading the investigation of the mystery structure. "It's so unexpected that it would never have entered your mind before."

The stone is at least 32 feet (10 meters) long in one of its dimensions. It is buried about 40 feet below the surface of a terrace on the western side of Monks Mound and well above the mound's bottom. Researchers believe it may be made of cobbles or slabs of limestone or sandstone.

Even if the apparent structure turns out to be no larger than this, it would be a dramatic find. Stone does not occur naturally at Cahokia (which is the Mississippi River valley about 20 miles (32 kilometers) southeast of St. Louis, Missouri--J.T.) so any stone would have had to be brought by humans. Stone is uncommon at excavations there.

"There's no question this is a unique discovery," said Melvin Fowler, an archaeologist at the University of Wisconsin at Milwaukee. "It's totally unexpected."

Fowler, reached by telephone in his office Friday, is widely considered the godfather of Cahokia archaeology.

Cahokia Mounts is the largest archaeological site in the United States and has the biggest mounds and the greatest number of mounds anywhere. The site is named for a sub-tribe of Illini Indians who lived there when the French arrived in the 1600s. At its peak around 1100 A.D., the area was covered with a community of 20,000 people.

The mystery was discovered about 10 o'clock on a cold, windy Saturday morning amid snow flurries as workers drilled into the western side of the mound.

Andy Martignoni Jr. and Steve Fulton, both SIUE archaeologists, were on duty at the site when the drill operator reported hitting a rock about 140 feet into the side of the hill. He drilled on, but the drill bit broke after cutting through about 32 feet of rock. Martignonia and Fulton talked the situation over for a few minutes.

"We talked about a possible drain, a tomb, al kinds of wild stuff," Martignoni said. Comparing the 'feel' of the drill with countless other operations, the drill operator told them the structure seemed to be made of large stones apparently placed together.

Martignoni called Woods, who had just gone to bed after staying up all night writing a report.

"You won't believe this," Martignoni told him. "We hit some stone at Monks Mound."

Woods and his collegues plan to investigate the finding this summer without harming the mound. Investigative techniques to be used will include seismic waves, drilling and testing for electromagnetic impulses.

(See the St. Louis Post-Dispatch for March 9, 1998, "Cahokia mounds finding stuns archeologists -- A large stone under the site's biggest mound may be a man-made structure," by William Allen, Post-Dispatch Science Writer. Many thanks to Lou Farrish of UFO NEWSCLIPPING SERVICE for forwarding the news article.)