It is speculated that the first humans to see St. Joseph Island and set foot on it were the hunter-gatherers of the Plano cultures who travelled north from the Great Plains of the continent between 9000 BCE and 6000 BCE. These peoples followed the bison and other animals into the areas revealed by retreating glaciers. Evidence of Plano migrations – particularly projectile point tools - has been found in the Great Lakes basin from Lake Superior through the St. Marys River to the north channel of Lake Huron.