Canadian Shield— also called the Precambrian Shield, Laurentian Shield, Bouclier Canadien (French), or Laurentian Plateau— is a large shield covered by a thin layer of soil that forms the nucleus of the North American craton. It has a deep, common, joined bedrock region in eastern and central Canada and stretches North from the Great Lakes to the Arctic Ocean, covering half the country. It also includes most of Greenland and extends into the United States as the Adirondack Mountains and the Northern Highland.