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Bison Restoration

Bison used to number in the millions on the Great Plains, but animals in conservation herds now number less than 20,000 and are considered “near threatened.”

Because most herds are less than 500 on small landscapes, scientists have agreed that bison have become ecologically extinct. This means they no longer play the critical roles in shaping prairie biodiversity.

An Icon of the West

The plains bison, also commonly known as the buffalo, is an iconic symbol of the free and open spirit of the North American prairie. While tens of millions of bison, described as “innumerable” by early 18th century European explorers, once roamed the Great Plains, only an estimated 500,000 bison remain in North America today. Of these, less than 4% (about 19,000 bison) live in conservation herds. Most of the bison on the landscape today are raised for commercial purposes. 


Photo by Erik Goldstein

Senior Bison Restoration Manager Scott Heidebrink conducts aerial surveys of the bison herd twice a year to assess population sizes and birth rates. As of fall 2019, the bison population is: 



The Herd on American Prairie Reserve

We restore bison to their original habitat on American Prairie Reserve lands, providing visitors a chance to witness the majestic species that astounded the earliest explorers and played a central role in the culture and spirituality of Native Americans. Thanks to donors and collaborators, the Reserve reintroduced bison on our lands in 2005, returning a species that had been gone from the landscape for more than 120 years. Learn more about the herd:




As part of APR’s desire to make a positive contribution to bison restoration efforts across the country, we have donated bison to conservation herds on the Fort Niobrara National Wildlife Refuge in Nebraska and the Rocky Mountain Arsenal National Wildlife Refuge in Colorado, as well as the Fort Peck Indian Reservation, Colorado State University, the United States Department of Agriculture and the Bronx Zoo. In 2014, two female bison calves from the APR herd became national ambassadors at the Smithsonian’s National Zoo in D.C.