The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains. They are distinct from the American Rockies in that they are primarily composed of layered sedimentary rock like limestone and shale, and have been more heavily shaped by glaciation, resulting in sharper, more jagged peaks and U-shaped valleys. The range is home to five national parks, four of which (Banff, Jasper, Kootenay, and Yoho) combine to form a UNESCO World Heritage site. The Columbia Icefield, located in the range, is one of the largest accumulations of ice south of the Arctic Circle; it feeds eight major glaciers and three of North America's largest rivers. The mountains are a habitat for iconic wildlife like grizzly bears, mountain goats, and elk, and are a premier global destination for mountaineering and winter sports.