The Mackenzie Bison Sanctuary’s population of about 2,000 wood bison is just a small fraction of the almost 200,000 shaggy, bearded beasts that once ranged throughout northern Alberta, northeastern British Columbia, southern Yukon, and the southwestern Northwest Territories. But it is a vast increase from the wood bison’s 1891 population low of 200 - 250 animals that resulted from years of over-hunting during the 18th and 19th centuries.

Today, the Mackenzie Bison Sanctuary, covering 10,000 square kilometres on the west side of Great Slave Lake, contains the world’s largest wild wood bison herd, and represents the first successful transplant of healthy wood bison into historic range.

The foundation of the Mackenzie Sanctuary was established in 1963, after Canadian federal wildlife officers located a herd of pure, wild wood bison in the Nyarling River area of Wood Buffalo National Park, south of Great Slave Lake. The newly-identified herd was remarkably free of the tuberculosis and bovine brucellosis that had been introduced to Wood Buffalo when infected bison from Wainwright, Alberta were transplanted to the newly-created reserve during the 1920’s.

Following the discovery, 18 of the healthy animals were captured and released in the Mackenzie Bison Sanctuary. By 1989, the Mackenzie Herd, as it is now known, had grown to about 2,400 bison. During the 1990’s, the herd suffered some reversals, due to wolf predation, a catastrophic drowning in 1989, and an outbreak of anthrax in 1993. Numbers have now stabilized at about 2,000, and recreational hunting – regulated by means of a Limited Entry Draw for resident hunters, and a designated outfitter for non-residents hunters - is now permitted in the Sanctuary. Less than 50 bison a year are harvested.

Bison Buffer: Since 1987, a Bison-Free Management Area, located between Wood Buffalo National Park and the Mackenzie Bison Sanctuary has separated the Wood Buffalo and Mackenzie Herds. The goal of the Bison Control Area, as it is also known, is to prevent the spread of tuberculosis and brucellosis from the southern herd to the Mackenzie animals. Both ground and aerial surveys of the area are carried out during winter months, when visibility of the bison is high, and when freezing of the Mackenzie River makes movement of the herds more likely. Any bison found within the Bison Control Area are removed. Resident hunters who encounter a bison within the Management Area are permitted to harvest it for meat, but they are required to report the kill.

Other free-roaming wood bison herds in the North West Territories are located in the Liard River Valley (Nahanni Herd), Slave River Lowlands (Hook Lake and Little Buffalo Herds), Chan Lake Territorial Park and Wood Buffalo National Park.

Wood bison were declared a “protected species” by the North West Territories government in 1964. In 1977, the Committee on the Status of Wildlife in Canada (COSEWIC) designated the wood bison as “Endangered,” but recent increases in the total population have shifted the designation to “Threatened.”