Almost like mice through a maze, hunters 9,000 years ago in an area currently covered by 120 feet of Lake Huron water built stone structures meant to corral caribou for easier hunting, Live Science reported. A series of lanes and dead ends put caribou exactly where hunters wanted them for the easy kill.

The stone structures only increased the spot's profile among the area's nomadic hunting groups. In addition to netting a fair amount of caribou meat, they used the location to share information and possibly even hold marriages.  

"For mobile hunters, this is a really valuable time, because they share information, they trade, they have marriages, they do all these things that you only do when you get a critical mass of people together," co-author John O'Shea, a researchers at the University of Michigan's Museum of Anthropological Archaeology told CBC News.

"This is, I think, giving us a really unique picture of what that whole annual cycle was that these hunters were following. The fact that all of the migrations tend to converge on these two locations ... would have provided predictability for ancient hunters, which is why we see so many structures located in these spots," O'Shea added.

The discovery also helped establish missing components of the archaeological record. About 9,000 years ago, researchers determined the former hunting grounds/current section of Lake Huron was a land bridge from northeast Michigan to southern Ontario, according to Live Science. O'Shea described conditions as "cold," "windy," and "unpleasant," but also prime for hunting, given the aquatic surroundings.

Caribou were typically hunted in the fall, not because of specific weather conditions, but because that's when they were fattest and most likely to traverse the land bridge. Researchers also found evidence that they were hunted in the spring, too, -- with slightly less success. That's when the caribou went from Ontario back to Michigan.

"We were surprised by the apparent seasonal differences between the different kinds of structures," O'Shea said.