Lake Agassiz

NASA

Farming in Ancient Lake Agassiz

Editor’s Note: Today’s story is the answer to the May Puzzler.About 15,000 years ago, southeastern Manitoba sat beneath tens of meters of frigid water. Lake Agassiz—which once encompassed present-day Lake Manitoba, Lake Winnipeg, and Lake of the Woods—covered an area larger than all of the Great Lakes combined. It formed in front of the retreating Laurentide Ice Sheet, which dammed rivers that otherwise…