Nahanni National Park has grown up—and out—by more than six times its former size. The massive expansion, announced on June 9 by the government of Canada and the Dehcho First Nation, brings the park’s area up to 12,000 square miles. Field studies of wide-ranging wildlife conducted by WCS-Canada played a key role in the decision to expand this globally important wilderness area in the Northwest Territories.

“Nahanni is one of the great natural areas in the world,” said Dr. John Weaver, who studied grizzly bears, woodland caribou, and Dall’s sheep in this remote region during 2002–2007. “The previous boundary was too narrow and too small for these big animals, and this expansion will protect critical habitat for these vulnerable wildlife species.”

Expansion of the park makes it one of the largest in the world—three and a half times the size of Yellowstone National Park—with no roads and no major trails. Nahanni lies within the traditional territory of the Dehcho indigenous people, who were directly involved in the expansion process.

An additional 3,000 square miles in the South Nahanni River headwaters has also been withdrawn from development for consideration as a separate but contiguous national park in the territory of the Sahtu people.

“The studies carried out by Dr. Weaver provided the solid scientific basis for revising the park’s boundary to help ensure its ecological integrity,” said Dr. Stephen Woodley, chief scientist for Parks Canada.

“This momentous decision by the Canadian government represents a new way of thinking about conservation at larger scales,” said Dr. Justina Ray, executive director of WCS-Canada.