I've shot 5 of them but none of them were free ranging in UT,AZ or SD. I got mine off of big ranches in either WY or MT. There are several ranches that raise bison for the meat market but that market is fairly small and they try to keep the herds in check and don't want them getting too big or they would flood the market and kill the price. So these ranches often want to take out young heifers before they get the chance to calve. All the bison I have taken were yearling heifers for meat.
Bison aren't a really difficult animal to hunt, that's why they could slaughter them by the millions in the 1870s. Once you locate them and even on those big ranches that can take some looking, it is merely a point of picking the one you want. They are big and the carcass is hard to handle. That thick hair is full of dirt and grit and is really tough on knife blades.
This one came off a ranch in MT. we found a small herd raiding some haystacks for the cattle in a remote pasture on a 100,000 acre ranch outside of Billings. A bison like this will give you about 350-400 lbs of meat.