That is going on in many tribes in California also. I know a guy who has a pen with catwalks over it, since one cannot safely enter a pen with the wilder ones, and they will hook a horse with their horns if given the opportunity.
Cool thing about spreading bison around is that they are very mobile if allowed to, and in climate change, they can handle extremes of temperature and grass does and will likely grow into the future. They were the most successful of the Pleistocene mega-fauna survivors, elk still thrive and nowadays use elevation on mountainous terrain as a survival strategy, in the distant past they were plains animals also.
There are still unfilled niches from the demise of the mammoths and woolly rhinos that will be available if we ever get out of the way. The niches for steppe grazers and browsers is pretty open, something will fill it if given the opportunity.