Beefalo
Most current bison herds are genetically polluted or partly crossbred with cattle. There are only four genetically unmixed American bison herds left, and only two that are also free of brucellosis: the Wind Cave bison herd that roams Wind Cave National Park, South Dakota; and the Henry Mountains herd in the Henry Mountains of Utah. A herd on Catalina Island, California  is not genetically pure or self-sustaining.