WCS Canada

Nahanni National Park Reserve

The legendary South Nahanni River watershed in the Northwest Territories encompasses one of the largest intact wildlands remaining in North America, and it was one of the world's first World Heritage Sites. Nahanni National Park Reserve was established in 1972 to protect a portion of the river corridor that includes the deepest river canyons in Canada, large hot-springs mounds, and the iconic Virginia Falls (which is twice as high as Niagara). In addition to its impressive geological features, the area provides habitat for wide-ranging animals such as grizzly bears and woodland caribou. 

Conservation Challenges

Over time, park officials recognized that Nahanni National Park Reserve was likely too small and too narrow for wide-ranging, vulnerable animals. Moreover, several notable geological features had been left out of the initial park. Pressure for mining, oil, and gas exploration along the park’s boundary was increasingly threatening the integrity of the park and the larger Nahanni watershed.

Conservation Approach

A team with representatives from Parks Canada and the Dehcho First Nation was chartered by the federal government as the first step to expand Nahanni. WCS conducted research on three focal species — grizzly bear, caribou and Dall’s sheep — on behalf of Parks Canada to help define new park boundaries. Over five years (2002-2006), WCS’s Dr. John Weaver conducted extensive, non-invasive DNA analysis of grizzly bears to map their distribution and relative abundance, discovered new karst (limestone) caves close to which Dall’s sheep and their newborns feed on lush grasses (a phenomenon found nowhere else on the continent), and found that distinct herds of caribou that winter inside the park migrate 250 km to their calving sites -- including areas in the Yukon Territory. These studies provided evidence that many of the critical areas for this wide-ranging wildlife were outside the park.


The studies carried out by Dr. Weaver provided a solid scientific basis for revising the park’s boundaries and played a central role in the Government of Canada’s decision in June 2009 to expand Nahanni National Park Reserve. The decision enlarged the park nearly 7-fold, from 4,822 km2 to 31,000 km2, including 80% of the South Nahanni River watershed and adjacent karst features. This made the park one of the largest in the world -- 3.5 times the size of Yellowstone National Park -- with no roads and no major trails. In August 2012, the Government of Canada also announced a new abutting National Park called Nááts'ihch'oh in the Nahanni headwaters, but unfortunately this smaller park does not encompass the entire headwaters area and excludes most of the critical calving and summer range for the South Nahanni caribou herd that winters in Nahanni National Park Reserve.

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WCS Canada
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