Answer:
Lake Iroquois formed at the end of the last Ice Age 16 thousand years ago.
Step-by-step explanation:
Lake Iroquois was a large proglacial lake that formed at the end of the last Ice Age, when the retreat of the Laurentide Ice Sheet allowed meltwater to accumulate in the area now occupied by the Great Lakes. Lake Iroquois existed between about 13,000 and 12,000 years ago, before the St. Lawrence River and the Niagara River eroded through the moraines that held the lake in place and drained it to the Atlantic Ocean.