BILLINGS, Mont. - Environmental and animal rights groups have been granted a last-minute hearing before a federal judge on their request to stop upcoming wolf hunts in the Northern Rockies.

Wolves across much of the region were removed from the endangered species list earlier this year.

Public hunts for the predators - the first in the Lower 48 states in decades - are scheduled to begin Sept. 1 in parts of Idaho and two weeks later in Montana.

Combined, the two states authorized hunters to take 295 of an estimated 1,350 wolves, or about a fifth of the animal's total population.

Groups including Defenders of Wildlife and the Humane Society of the United States last week asked for a court injunction to bar the hunts. On Monday, U.S. District Judge Donald Molloy said he would hold a three-hour hearing next Monday in Missoula, Mont., to hear arguments in the case.

"We have to move quickly and hope the court can accommodate our request," said Doug Honnold with the environmental law firm Earthjustice, which is representing the plaintiffs. "From our standpoint, we would prefer that not a single wolf is shot in the hunts."

State officials say they have no intention of wiping out wolves but need to get wolf attacks on livestock under control. In one case earlier this month on a ranch south of Dillon, Mont., a pack of wolves killed an estimated 120 sheep - possibly the highest toll ever recorded since the predators were returned to the area.

Hunting tags went on sale Monday in Idaho. Outlets that sold the tags reported a brisk business driven primarily by in-state hunters also buying deer or elk hunting tags.

Montana's tags are to go on sale next Monday.

Although Alaska has long hosted annual wolf hunts, the animal had been wiped out almost completely elsewhere in the country until 1995. That's when the government began reintroducing them in the Northern Rockies over the objections of the region's livestock industry and many state officials.

The population has since boomed, surpassing the U.S. Fish and Wildlife Service's original recovery goal of 300 animals earlier this decade. But environmentalists insist wolves remain threatened and that hunting could help drive them again toward extinction.

In 2008, there were a record 601 cattle, sheep, llamas, dogs and other domestic animals killed by wolves across the Northern Rockies.

The killings have continued this year, and state officials say they could grow more frequent if Molloy again sides with the environmentalists.

"The (wolf) population continues to grow," said Joe Maurier, director of the Montana Department of Fish, Wildlife and Parks. "We will continue to have (livestock killings) across the landscape. It's just going to take more and more effort to keep that situation under control."

Molloy already has sided with environmentalists once, in a case last year that forced the federal government to rescind an earlier attempt to take the wolves off the endangered list. That proposal was later revised and wolves were declared officially recovered in Idaho and Montana in March.

About 300 wolves in neighboring Wyoming remain on the endangered list. That population also is considered recovered, but they were kept on the list largely because of a state law allowing the predators to be shot on site across most of Wyoming.

Government wildlife agents and ranchers protecting livestock killed 264 wolves in the Northern Rockies in 2008, including 21 entire packs, according to the U.S. Fish and Wildlife Service.