WASHINGTON -- Federal officials are trying to figure out how to control a herd of about 350 bison that is roaming the North Rim of the Grand Canyon and damaging vegetation and water sources there.
The herd, which had been managed before through hunts, has been out of reach since the animals wandered into Grand Canyon National Park several years ago, where they cannot be hunted.
"They stay in the park because they understand they're protected inside," said Diane Chalfant, Grand Canyon deputy superintendent.
Although it will take close to two years of study and public input to develop a final plan, Chalfant said one option being looked at is finding ways to get the bison out of the national park and on to state lands where they can be hunted.
The animals are not native to the Grand Canyon but were brought to northern Arizona more than 100 years ago, as part of an experiment to breed a bison-cattle hybrid.
The herd was sold to the state in 1925, and in 1950 the animals were placed in the House Rock Wildlife Area under the control of the Arizona Game and Fish Department. Their numbers were maintained at about 100 animals through hunting.
But they migrated in the past 20 or 30 years, ending up in the hunt-free Grand Canyon, Chalfant said. There are now so many bison in the canyon that "we're beginning to see more and more impacts on the park," she said.
Previous discussions about moving the herd made no headway, but those talks were rekindled by the amount of damage being done by the bison now. The animals are carving large wallows near water sources and overgrazing vegetation, crowding out native animals and leading to runoff.
The National Park Service notice published in Friday's Federal Register said other state and federal agencies will be involved in the development of any plans, which would be aired at public hearings before any decisions are made.
"We want to get a sense of where the public is coming from on this," Chalfant said. But she said the park service is currently leaning toward moving the bison to hunting areas where their numbers can be managed.
Sandy Bahr, director of the Grand Canyon chapter of the Sierra Club, agreed that the bison probably need to be moved to a place where they can be hunted - but by natural predators, like wolves, not people.
"Their predators … help to keep their population at a more sustainable level," Bahr said. "Hunting does not mimic that."
Bahr said a species survives when the strongest survive, but that hunters tend to shoot those large "trophy" animals instead of the weaker, smaller animals that natural predators take. Because of that, she said, hunting could cause significant damage to the herd.
Simply moving the bison outside the park boundaries will not solve the problem, Bahr said, since they will just walk back in to the park where they are not in any significant danger.
"These animals don't read maps," she said. "You can't just say, ‘OK, here's the park boundary and stay outside of the boundary.' That just doesn't work."
She said the park service should consider moving the bison so far from park boundaries that they will not be able to migrate back.