Archaeologists from the Cleveland Museum of Natural History have uncovered 4,000-year-old clay floors.
So far, the team led by Brian Redmond have uncovered a three-inch-thick floor made from layers of yellow clay that was carried to the site in Ohio.
"There's nothing like this anywhere in Ohio. It's very significant, a much more significant site than we previously thought," Redmond told cleveland.com. "These are house structures. This was like a village site."
The builders lived in what archaeologists classify as the Late Archaic period in North America, so far back that they don't have a tribal name.
"We have no idea what they called themselves or what language they spoke," Redmond said.
The uncovered floor, which is about three inches thick, is built of layers of yellow clay that was carried from nearby areas. An unmistakable basin is built into it, as are cooking pits and storage holes that held hickory nuts, which were an important source of nutrition.
They believe they have also found evidence of hickory saplings that would have been tied together, wigwam-style, in a framework for the prehistoric house.
"A small family would be very comfortable. They were well insulated, and sheltered under the tree canopy of oaks," Redmond said. "Unlike at other sites, they're going to the trouble to make floors. They're here for months at a time."
They were not people indigenous to Northeast Ohio, he said, but migrants from the southeast, most similar to tribes found in northwest Kentucky and southern Illinois.
Every few years, if not annually, for 200 or 300 years, their travels would bring them to the site in Lorain County to spend the winter months.
They were hunters and gatherers who lived before the advent of pottery or farming, and 2,000 years before mound building.