Montana officials filed a lawsuit on Dec. 31 in U.S. District court alleging that the DOI and NPS have failed to keep bison populations in check at Yellowstone National Park. NPS officials say the park can support a larger herd,

State officials say they're worried about bison passing on disease to cattle outside the park—but wildlife managers say it's never happened before.

Gov. Greg Gianforte and two state agencies are suing the federal government. They argue Yellowstone National Park’s new bison management plan violates federal law.

The lawsuit is the latest escalation in a decades-long fight between state and federal officials over how to manage the park's growing bison population.

Montana alleged the Yellowstone National Park bison herd population has grown to a potential harmful level.

State warns that it could rescind ‘tolerance zones’ that allow bison to wander out of the park without being hunted.

Montana is suing Yellowstone National Park over a plan to increase the number of bison in and around the park and establish greater tolerance for their presence outside its boundaries.