What is now part of Lake Huron's obscured floor became a dry land bridge between modern-day Presque Isle, Mich., and Point Clark, Ontario when lake levels dipped some 7,500 to 10,000 years ago. But could it have been a rich hunting ground for Paleo-Indians?

Previous wisdom has held that "most [sites] are presumed lost forever beneath the lakes"—which were carved out and filled in by receding glaciers about 10,000 years ago—note the authors of a new study, published today in Proceedings of the National Academy of Sciences, which has found traces of what appear to be stone structures, hunting blinds, dwelling sites and caribou drive lanes hidden under the mussels and algae at the bottom of the lake.

Using sonar and remote-operated vehicles, the research team from the University of Michigan at Ann Arbor's Museum of Anthropology and Marine Hydrodynamics Laboratory surveyed about 28 square miles (72 square kilometers) as deep as 492 feet (150 meters) below the lake's surface along the now-submerged Alpena-Amberley ridge. Among the findings was a 984-foot- (300-meter-) long structure that match caribou driving lanes (a long precursor to the modern cattle chute, which directed herds of caribou into an area where they could be killed) documented on dry land on Canada's Victoria Island.

The findings "raise the possibility that intact settlements and ancient landscapes are preserved beneath Lake Huron," the study authors write. They hope to soon send in autonomous underwater vehicles and scuba-diving archeologists to search for smaller, more detailed artifacts.

Image of a possible hunting blind made from three boulders below Lake Huron courtesy of John O'Shea/University of Michigan