The caribou would come in the morning—forced through the narrow strip of marshland where he camped. In that moment, two glassy flakes splintered away from the point of impact and fell to his feet. The samples were recovered from the Alpena-Amberley Ridge, a geologic formation below Lake Huron that connects Michigan to Ontario. Stone tools recovered from the Alpena-Amberley Ridge are much smaller than artifacts found nearby that date to the same time period. This suggests that a group of ancient people, with a different way of life and system of hunting, existed on the ridge around 9,000 years ago.