Fathoms beneath present-day Lake Huron, early Americans once stood on dry land, hunting caribou as the animals migrated between southern Ontario and northeastern lower Michigan.A team led by University of Michigan researchers drew international attention when they announced those findings a decade ago, after discovering rock arrangements indicative of prehistoric hunting camps on a lake bottom ridge.But far less fanfare has followed the scientists in years since, as they've pieced together an increasingly clear picture of life 10,000 years ago in the now-submerged subarctic grassland...They've discovered fragments of tools that look nothing like other Great Lakes artifacts from a similar...