An underwater ridge in Lake Huron, one of the five Great Lakes in the Michigan-Canada region, has been found to be the site of an ancient caribou hunting structure. For hundreds of years, Lake Huron has been sitting atop an intricate design of stones, used, presumably by natives, to help guide caribou herds across what was at that time an exposed land passage and also a crossing from one mass of land to another (what are now Michigan and Canada).
This caribou hunting structure has never been discovered until now, because on top of this ridge there is now 120 feet, or 347 meters, of water in its place. The ridge is called the “Alpena-Amberly Ridge,” and would have connected what is now the northeast part of Michigan to what is now southern Ontario.
The land mass would have been exposed due to conditions caused by the dryness of the last Ice Age, before the melting conditions arose that caused the water to cover the lands and be placed where it is now (forming the Great Lakes). Researchers at the University of Michigan in Ann Arbor, Michigan, estimate that the structure is roughly 9,000 years old, and that it spans a total area of about 92 feet by 330 feet (which is 28 by 100 meters).
There were also tools that scuba divers, who also investigated the site uncovered, which further provided evidence that the site that they had found had indeed been an ancient caribou hunting structure. Chipped stone flakes were found near Lake Huron, which may have been used either to sharpen stone tools or to keep them in shape.
Using a remotely operated vehicle, or ROV, with a video camera, and underwater sonar, researchers were able to detect two lines of stones running parallel to each other and creating a lane running in a northwesterly direction. The lane of stones ran about 28 feet (8 meters) wide and about 98 feet (30 meters) long, and ended in a circular shape, similar to a cul-de-sac. Additionally, the orientation of the lanes made them optimal for native hunters to catch the caribou in both of their migrations. Although fall would have been the preferred time to catch caribou, as they were the most well-fed at that time of year and their hides were also the best at that time, the structures were set up to help hunters catch them both in the autumn and the spring. In the autumn, the caribou traveled southeast for the winter, and in the spring, they traveled northwest, back to where they bred their offspring.
Researchers suggested that larger groups of hunters worked together in the spring to trap the caribou, while smaller groups worked more separately in the fall to capture them. The researchers said that they were surprised at the differences between the two hunting structures for fall and spring.
Much like the caribou hunting structure that Lake Huron has been found to be sitting atop of, structures of a similar variety have also been uncovered in the North American Arctic region; however, not many of them have actually been preserved or maintained due to modern day road building and farming.
By Laura Clark