Bison Pet

Simultaneously, two Montana ranchers, Michel Pablo and Charles Allard, spent more than 20 years assembling one of the largest collections of purebred bison on the continent (by the time of Allard's death in 1896, the herd numbered 300). In 1907, after U.S. authorities declined to buy the herd, Pablo struck a deal with the Canadian government and shipped most of his bison northward to the newly created Elk Island National Park. Also, in 1907, the New York Zoological Park sent 15 bison to Wichita Mountains Wildlife Refuge in Oklahoma forming the nucleus of a herd that now numbers 650.
An isolated bison herd on Utah's Antelope Island has also been used to improve the genetic diversity of American bison. The current American bison population has been growing rapidly, and is estimated at 350,000, compared to an estimated 60 to 100 million in the mid-19th century. Most current herds, however are genetically polluted or partly crossbred with cattle. Today there are only four genetically unmixed herds and only one that is also free of brucellosis: it roams Wind Cave National Park. A founder population of 16 animals from the Wind Cave herd was established in Montana in 2005 by the American Prairie Foundation. The herd now numbers near 100 and roams a 14,000-acre (57 km2) grassland expanse on American Prairie Reserve.
One of the largest privately owned herds, numbering 2,500, in the US is on the Tallgrass Prairie Preserve in Oklahoma which is owned by the Nature Conservancy. Ted Turner is the largest private owner of Bison with about 50,000 on several different ranches.
The only continuously wild bison herd in the United States resides within Yellowstone National Park. Numbering between 3,000 and 3,500, this herd is descended from a remnant population of 23 individual mountain bison that survived the mass slaughter of the 1800s by hiding out in the Pelican Valley of Yellowstone Park. In 1902, a captive herd of 21 plains bison was introduced to the Lamar Valley and managed as livestock until the 1960s, when a policy of natural regulation was adopted by the park.