Remains of prehistoric habitat under the Great Lakes

Fascinating stuff!
The vids are from about 2 years ago.

From YahooNews:
 ....Archaeologists have discovered sophisticated prehistoric stone walls deep beneath the surface of Lake Huron that give the clearest portrait yet of the mysterious people who lived in the Great Lakes region at the end of the Ice Age.
"It's just way more complex than anything we've seen before," said John O'Shea, a University of Michigan archeologist who published his findings Monday in the Proceedings of the National Academy of Science.
Since 2008, O'Shea and his colleagues have been investigating an underwater ridge in Lake Huron that runs roughly between Alpena, Mich., and Point Clark, Ont. As the glaciers were beating their final retreat about 9,000 years ago, water in the lake was about 100 metres below today's level and the Alpena-Amberley Ridge was exposed.

That ridge formed a narrow corridor between what is now northern Michigan and southern Ontario. Its subarctic environment of tamarack, spruce and wetland made it a perfect migration route for vast herds of caribou that roamed the area.
"They were massive," said O'Shea, who suggests those herds were at least equal to the tens and hundreds of thousands of animals that make up modern caribou herds in the Canadian Arctic.
"I'm imagining seas of animals going through there."
The paleo-Indians who were moving onto land the glaciers were slowly exposing made good use of the animals. O'Shea has found more than 60 stone constructions under the water that are likely to have been used as hunting blinds.
But his most recent discovery is far and beyond his other finds.......