Wood bison (Bison bison athabascae) are the largest native terrestrial mammals in North America. They are currently listed as a threatened species (Species at Risk Act - SARA). The wood bison herd at Elk Island National Park was established in 1965 from individuals from Wood Buffalo National Park. Located 45 km from Edmonton on the south side of the Yellowhead Highway, the Elk Island National Park wood bison herd roams a 60 sq km roadless enclosure, wandering the hills and foraging along the lakes and wetlands. The herd was intended to serve as a source of disease-free and genetically pure animals for reintroduction projects nationally and internationally, contributing to the recovery of the species. A majestic animal, wood bison are an average of 3.9 m long, and a bull has an average mass of 840 kg (~1850 lbs). Currently, there are 320 wood bison in the park. They can often be seen along the fenceline or by hiking the Wood Bison Trail.