Native Americans, ranchers, government officials, and environmental activists battle over the yearly slaughter of America's last wild bison, based on fear that migrating animals will transmit the disease brucellosis to cattle. Join a 500-mile spiritual march across Montana led by Lakota elder Rosalie Little Thunder expressing her people's cultural connection to bison, an environmental group engaging in civil disobedience and video activism, and a ranching family caught in the crossfire.

• ITVS