The Fort Peck Assiniboine and Sioux Tribes, along with four other groups, are seeking to join a federal lawsuit against Yellowstone National Park’s bison management plan. The State of Montana is challenging the plan, arguing that it increases the risk of brucellosis transmission to cattle. The tribes contend that Montana’s efforts undermine their treaty hunting rights and limit food sovereignty. They emphasize the park’s progress in disease management, such as vaccination programs and herd monitoring, and the positive impact on bison transfer to tribal lands.