The Mackenzie bison population is the largest healthy, free-roaming bison population in the NWT. The herd was established in 1963 and grew rapidly. In 1989, it reached an estimated 2,431 bison. Since then, population growth has declined.
In 2000, the population stabilized at about 2,000 bison. Several mortality factors contributed to this stabilization in numbers, specifically an anthrax outbreak in 1993 killed 172 bison. In 1989, 177 bison fell through thin spring ice and were drowned. Since 2000, numbers slowly declined to about 1,440 bison by early 2012.
During the summer of 2012, about one-third of the Mackenzie bison population was lost to an outbreak of anthrax. The population now numbers about 700 animals.
Harvesting in the Mackenzie wood bison range has been closed since November 1, 2012. No harvesting of Mackenzie wood bison in the range is allowed.
The Mackenzie wood bison population occupies a wilderness area of approximately 20,000 km2 ranging from the Mackenzie River near Fort Providence north to areas near Yellowknife. This range has expanded west of the NWT Highway 3 to include both the Mills and Mink lake areas.