For the purpose of permanently commemorating the long-existing relationship of peace and good will existing between the people and Governments of Canada and the United States and upon the enactment by the proper authority of the Canadian Government of a similar provision respecting the Waterton Lakes National Park in the Province of Alberta, and upon the proclamation of the President of the United States, who is authorized to issue such a proclamation, the Glacier National Park in the State of Montana shall become a part of an international park to be known as the Waterton-Glacier International Peace Park.