Glacier National Park borders Waterton Lakes National Park in Canada — the two parks are known as the Waterton-Glacier International Peace Park, and were designated as the world’s first International Peace Park in 1932. The parks were designated by the United Nations as Biosphere Reserves in 1976, and in 1995 as World Heritage sites.
Glacier National Park is a stunning display of the geological processes that changed North America over the last billion years. The rock formations in the park are almost entirely sedimentary, laid down between 1600 to 800 million years ago when this area was an inland sea. They were uplifted during the formation of the Rockies beginning around 170 million years ago, and today contain some of the best Proterozoic fossils in the world. The mountains were carved into their present form by the advance and retreat of glaciers during the last ice age, and the park, as its name suggests, contains an abundance of glacial features, including lakes, valleys, and remnant glaciers (although these have diminished significantly in the last century).