Waterton Lakes National Park, 203 sq mi (525 sq km), SW Alta., Canada, SW of Lethbridge and at the U.S. border, adjoining Glacier National Park, Mont.; est. 1895. It is the Canadian section of Waterton-Glacier International Peace Park, created (1932) by acts of the Canadian Parliament and the U.S. Congress. The area is mountainous, rising to c.9,600 ft (2,930 m) at Mt. Blakiston, and contains the Waterton Lakes, the largest of which extends across the border into Montana.