What is now part of Lake Huron's obscured floor became a dry land bridge between modern-day Presque Isle, Michigan (USA), and Point Clark, Ontario (Canada) 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" note the authors of a new study, published 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 km) as deep as 492 feet (150m) below the lake's surface along the now-submerged Alpena-Amberley ridge. Among the findings was a 984-foot- (300-m-) 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.
     "This is the first time we've identified structures like these on the lake bottom," said co-author John O'Shea, curator of Great Lakes Archaeology in the Museum of Anthropology and professor in the Department of Anthropology. "Scientifically, it's important because the entire ancient landscape has been preserved and has not been modified by farming, or modern development."
     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.
     The Paleo-Indians were nomadic and pursued big game, O'Shea said. With the Archaic period, communities were more settled, with larger populations, a broad spectrum economy, and new long distance trade and ceremonial connections. "Without the archeological sites from this intermediate time period, you can't tell how they got from point A to point B, or Paleo-Indian to Archaic," O'Shea said. "This is why the discovery of sites preserved beneath the lakes is so significant."
     Perhaps more exciting than the hunting structures themselves is the hope they bring that intact settlements are preserved on the lake bottom. These settlements could contain organic artifacts that deteriorate in drier, acidic soils on land.

Sources: Scientific American, Canada.com (8 June 2009), Science Daily (9 June 2009)