One of America's great wildlife icons, the American bison, was nearly extirpated at the turn of the last century by hunters and was saved only because 25 of the animals found refuge in Yellowstone National Park. The offspring of those few surviving animals are today's Yellowstone bison herd, which, unlike domesticated ranch bison, are genetically pure. As the only wild, free-roaming bison to continuously occupy their native habitat in the United States, they are living links to the vast herds that once covered the western plains.

The National Park Service has, in recent years, turned from protecting Yellowstone's bison herd to facilitating their slaughter. These actions, undertaken in partnership with the Montana Department of Livestock, were triggered by unfounded fears that bison will transmit a disease called brucellosis to local cattle. (Brucellosis is not fatal to cows but can cause premature births of first calves.) As scientists have already pointed out, there has never been a recorded transmission of brucellosis from bison to cattle in the wild. Moreover, fewer than 500 cattle graze in areas where they might come into contact with the Yellowstone bison; the chances for interaction are further reduced in winter when those cattle are removed from the range while the bison search for food. Nevertheless, in March 2003, park rangers captured 231 bison within the park and shipped them off to slaughterhouses.

During consideration of H.R. 2691, the 2004 Interior appropriations bill, Representative Nick Rahall (D-WV) offered an amendment to prohibit the National Park Service and the U.S. Forest Service from using federal funds to kill bison in and around Yellowstone. On July 17, 2003, the House rejected the Rahall amendment by a 199-220 vote (House roll call vote 383). YES is the pro-environment vote.