This winter the state of Montana has shot 232 bison near West Yellowstone and 559 have been shot or sent to slaughter by the Park Service near the north entrance of Gardiner, Montana. This puts the total number of bison shot or slaughtered at 791 as of February 5. The herd of Yellowstone bison is the nation's last free-ranging bison population and are the remnant of the vast herds that were nearly annihilated in the 19th century.
Some biologists fear a collapse in the bison population.
On February 4 a survey flight counted only 1982 bison in the Park. The bison are leaving the park because of the coldest winter on record since 1943. Arctic freezes separated by heavy rains have encased the park in ice as hard as cement. The bison cannot dig beneath the snow for food and are forced to leave the park. Additionally, increased snowmobiling accommodated by groomed trails have made it easier for bison to exit from Yellowstone into Montana.