HOUGHTON, Mich. — Officials plan to relocate several gray wolves from the Canadian province of Ontario to Isle Royale National Park this winter.

It’s the next step in rebuilding the depleted wolf population at the Lake Superior park. Only two remained until crews took four more wolves to the island from Minnesota this fall.

Plans call for transporting 20-30 mainland wolves to Isle Royale in the next few years. The predators are considered essential for keeping the park’s moose from overpopulating and eating too much of its greenery.