Wild Bison Restoration: Plains Ecosystem Return and Welfare

American bison were reduced from 30 million to fewer than 1,000 individuals in the 19th century. Successful conservation has rebuilt herds, and rewilding programs are restoring bison to their ecological role in North American grasslands.

Key Facts

American bison historically numbered 30-60 million, ranging across North America from Alaska to Mexico
Commercial hunting between 1870-1890 reduced bison to approximately 300-1,000 individuals
The current North American bison population is approximately 500,000, primarily in commercial herds
Genetically pure bison free from cattle gene introgression number approximately 20,000 in conservation herds
Yellowstone National Park hosts the only continuously wild bison herd in the US, numbering approximately 5,000
Bison are ecosystem engineers whose grazing, wallowing, and movement patterns create habitat diversity for hundreds of species
American Prairie Reserve in Montana is creating the largest wildlife reserve in the lower 48 states centered on bison restoration
Native American nations including the Lakota Sioux are leading bison restoration programs with cultural and ecological goals

Welfare Considerations

Bison welfare in conservation herds requires balance between maintaining natural behavior and managing for disease, genetics, and human safety. Wild-ranging bison in Yellowstone periodically test positive for brucellosis - a disease contracted from domestic cattle - creating conflict when bison migrate outside park boundaries. State management allowing hunting of migrating Yellowstone bison raises welfare and conservation concerns. Bison in restoration programs who have sufficient space to engage natural behaviors including wallowing, seasonal migration, and social bonding show healthy herd dynamics and individual welfare indicators. Bison in small commercial herds confined to limited space are unable to express natural movement and social behavior. The ecological restoration of bison benefits both bison welfare and grassland ecosystem health.

What You Can Do

Support American Prairie Reserve and other large-scale bison restoration initiatives
Donate to Native American bison restoration programs that integrate cultural and ecological restoration
Advocate for policies allowing bison migration outside Yellowstone without lethal management
Choose bison meat from conservation herds rather than commercial operations where available
Learn about the ecological role of bison and share this knowledge to build public support for restoration