Researchers have made a rare find that demonstrates how clever prehistoric hunters in North America could be—and it's at the bottom of Lake Huron of all places. Researchers at the University of Michigan found evidence of a network of hunting blinds they say was used to kill caribou on their seasonal migrations, reports LiveScience. The stone structures are now submerged under more than 100 feet of water, but they were on land about 9,000 years ago on a ridge that runs from northeast Michigan to southern Ontario. Essentially, the hunters of yore built stone "drive lanes" that the caribou would enter, unaware it was an ambush. The exact method was actually different based on which direction the animals were headed—the difference between spring and fall migrations.
If these structures "were on solid ground, (they) probably would've been bulldozed away for a Walmart parking lot by now," an archaeologist not involved with the study tells USA Today. Underwater archaeology may be pricey—this find required sonar and a remotely operated vehicle—but here "it's revealing a site that's in pretty much pristine condition." The discovery could shed more light on the hunting and migratory habits of the era, notes AP, because the system would have needed 15 or so people in the spring (though fewer in the fall). “The larger size and multiple parts of the complex drive lanes would have necessitated a larger cooperating group of individuals involved in the hunt,” says one of the UM scienists. “The smaller V-shaped hunting blinds could be operated by very small family groups relying on the natural shape of the landform to channel caribou toward them.”