BILLINGS, Mont. (AP) — An appeals court revived a lawsuit filed by an environmental law firm that challenged the U.S. government’s management of bison from Yellowstone National Park.

The decision by the 9th U.S. Circuit Court of Appeals reverses a lower court ruling from February that dismissed the lawsuit from the Cottonwood Environmental Law Center.

A three-judge appellate panel said Monday that by allowing hunting and hazing of bison, the federal government had taken actions that were a valid target of the lawsuit.

The panel returned the case to U.S. District Judge Sam Haddon for further proceedings and to decide if Cottonwood’s lawyers have valid claims against state officials in Montana, who are also named as a defendant.

Under a 2000 agreement between Montana and U.S. officials, bison leaving Yellowstone during their winter migration are hunted, captured for slaughter or hazed back into the park to prevent the spread of the disease brucellosis.

That agreement has been modified over the years to allow more tolerance for bison in some areas. Cottonwood’s lawsuit argues that a new environmental review of the capture and slaughter program is needed.