Make no mistake I am NOT a PETA person, however there several solutions to this so called over population of bison. I agree with Bassbod !! Step back, take a breath, and figure it out before we put these bison on the endangered list 20 years from now.
The North American bison aren't going extinct anytime within the foreseeable future.
There are about 500,000 bison that currently exist on private lands and around 30,000 on public lands which includes environmental and government preserves in North America. According to the IUCN, roughly 15,000 bison are considered wild, free-range bison not primarily confined by fencing.
Excess bison numbers can create habitat damage just as bad as overgrazing by catte, and the Yellowstone NP herd (the largest) is managed to maintain a proper carrying capacity. Once numbers of the herd migrate off NPS lands to winter range the excess number animals are first offered to Indian tribes in Montana and elsewhere for relocation once the animals are determined to be disease-free. And there is a hunting season in MT for both Indian and non-Indian off National Park lands.
Besides there is a bison farm close to where I live and a couple hundred bison are easily viewable there from a major highway year-round.
I can buy bison meat every day in local stores.