Stewart Knowitall is the Herald Review\u2019s go-to guy for answers on any subject. With his vast network of educated professionals, Stewart will help answer the questions confounding the minds of our younger readers. \u00a0Look for the answers he finds to questions from third graders across Osceola County once each month.\u00a0If you have a question for Stewart Knowitall, email email@example.com. Austin, your question is a great one! As you probably know,\u00a0a peninsula is a long piece of land that is surrounded by water on all sides except for one, where it is\u00a0connected to the mainland. Michigan\u2019s Upper Peninsula exists because of the Great Lakes that border\u00a0it on three sides: Lake Superior to the north, Lake Michigan to the south, and Lake Huron to the east.\u00a0 So the answer to your question is also about how and why these lakes formed where they did.\u00a0About 80,000 years ago a huge mass of glacial ice called the Laurentide Ice Sheet began to form and\u00a0spread southward from the Hudson Bay region in Canada, which is north of Michigan. We can know\u00a0from different glacial sediments and landforms that as the ice moved into the Great Lakes region it\u00a0traveled as several different lobes. These lobes of ice moved along stream valleys that already existed\u00a0around the Upper and Lower Peninsulas of Michigan. As they moved, the thick, heavy\u00a0ice lobes dug deeply into the rocks and carved the original valleys into long, deep basins. As the ice\u00a0lobes continued to move south they also covered the Upper and Lower Peninsulas but these areas were\u00a0highlands, so the ice was thinner, and they are made of harder bedrock than in the valleys. For these\u00a0reasons the glacier could not erode the two peninsulas as deeply as the basins. By about 20,000 years ago the ice sheet had reached south into central Ohio, Indiana, and Illinois.\u00a0After that it began to melt back to the north and eventually uncovered the Great Lakes region. The\u00a0deep basins carved by the ice lobes filled with water to become the Great Lakes and the harder rock\u00a0highlands were left standing above the lakes as the Upper and Lower Peninsulas of Michigan. We are\u00a0very fortunate to live in such a beautiful and special place of rock shaped by ice. Austin, I hope this has helped answer your question about how the Upper Peninsula formed. As to\u00a0why the peninsulas are made of harder bedrock than the lake basins, that is another story for another\u00a0time! For anybody who wants to learn more about the geology and geography of Michigan, an excellent\u00a0resource is Michigan Geography and Geology, 2009, edited by Randall Schaetzl, Joe Darden, and Danita\u00a0Brandt. Fred Heck Professor of Geology at Ferris State University He teaches non-geology majors about the Earth system through courses in Physical Geology, Historical Geology and Earth Systems Science. All of his classes include a day trip to Sleeping Bear Dunes National Lakeshore, and he has led students on two-week summer field trips to explore the geology of Michigan, the Canyon Country of southern Utah, and the national parks of the Rocky Mountain region.