American Bison

Hybridization is an issue with bison as most appear to have some genetics from cattle. I believe the Yellowstone herd and some of the herds derived from it are considered pure, but many bison apparently carry cattle genetics even though they look like bison.

They appear to be fenced in, so I wouldn't be surprised if that was the case. As I understand it the meat of the hybrids is in high demand

Interesting. I wonder if the light colored individuals are cattle/bison hybrids. White bison are extremely rare and to have this many in one place seems unlikely, if they are true bison.