Wolves have been re-introduced in Yellowstone

But there is anger over the plans in Idaho and Montana.

Idaho Governor, Dirk Kempthorne, says he fears for people's safety and has threatened to try to block the moves in the courts.

"No-one in Idaho wants these bears back," Mr Kempthorne said.

And he's supported by Senator Mike Crapo: "This is a plan that is being shoved down our throats."

Local involvement

Ralph Morgenweck of the U.S. Fish and Wildlife Service, who will be overseeing the move, says he intends to get local people involved so fears over safety can be laid to rest.

The grizzly bear return has been an emotional issue in Idaho and Montana ever since it was proposed it several years ago.

Wolves were successfully reintroduced into the Yellowstone national park five years ago.

Bears have found it difficult to survive in parts of Canada

But critics say the bears are a threat to ranchers and could harm the region's tourist business, especially in the popular Bitterroot Valley.

Federal officials have been trying to reassure local people saying there would be "zero tolerance" for bears that wandered onto private land and that they would be captured quickly or possibly destroyed.

Conservationists say the vast Selway-Bitterroot Wilderness and Frank Church-River of No Return Wilderness are ideal relocation sites for the bear, which is protected under the Endangered Species Act.

About 1,000 of the huge bears are thought to be in the United States, outside of Alaska.

They are concentrated in north-western Montana, including Glacier National Park, with a smaller number in the Yellowstone region.

Once more than 50,000 grizzlies roamed the West.

They were native to the Bitterroot region until hunters killed off many of them.