Grand Canyon National Park will be issuing 200 bison tags in an attempt to reduce the population.
The herd was introduced into the 1900's by a rancher who tried to cross breed them with cattle. He bagged it as a bad idea and Arizona's Fish & Game have been monitoring it ever since.
While the initial population was around a hundred the herd numbers are up to around 600. They're hard on the habitat and they want to manage the population as they're predicted to double in the next couple of decades.
So if you can lob a safari round accurately down range, and carry all your crap with you, you might get lucky and be able to draw out a tag on AZ's lottery system. The majority of the meat and hides will go to local tribes but you'll be able to get one too if you don't mind packing it out.