How long have Bison been kept at Golden Gate Park ?
In addition , though the bison on Antelope Island are Prairie bison , which was the most common bison subspecies in North America , the bison have a distinct genetic heritage from many of the other bison herds in the United States and they are considered to be desirable as part of the breeding and foundation stock for other bison herds , because of their separate genetic heritage and some of the distinct genetic markers that are found in the population .