At one time a couple of ranches in my home AO decided to dip their toe in the beefalo craze. They quickly found that bison are a bad combination of huge, dumb, and very very strong. Traditional livestock handling equipment is laughably inadequate, adults won't fit into stalls or chutes. You better have on helluva heavy-duty trailer to carry them, too. Fences mean nothing. A bison bull will walk through a five-wire fence without so much as a stumble, literally amble through them with no more effort than you or I would give to brushing aside weeds. Two bulls in a fight? Forget about anything in the vicinity, it's history (up to and including things like dump trucks and tractors). Unless your overhead tanks, grain bins, windmills, etc. are built out of 4" drill stem and mounted in concrete, bison will buckle the legs by rubbing on them. Same goes for fence corners and small outbuildings. They roam wherever they want, whenever they want. There's no way to contain them to a particular pasture short of a reinforced concrete wall, and even that better be damned stout.
Brad