In the Canadian Rockies, glaciers are generally larger and more widespread than to the south in the Rocky Mountains. One of the more accessible in the Canadian Rockies is the Athabasca Glacier, which is an outlet glacier of the Columbia Icefield. The Athabasca Glacier has retreated since the late 19th century. Its rate of retreat has increased since 1980, following a period of slow retreat from 1950 to 1980. The Peyto Glacier in Alberta covers an area of about , and retreated rapidly during the first half of the 20th century, stabilized by 1966, and resumed shrinking in 1976.