Seven conservation groups made good on a threat last week to file a lawsuit challenging a temporary federal rule that would loosen restrictions on when gray wolves can be shot in Montana, Wyoming and Idaho.

The legal documents filed in U.S. District Court in Missoula Monday morning ask that the new federal rule, also published Monday, be overturned, according to Louisa Willcox with the Natural Resources Defense Council. The case has been assigned to Chief Judge Donald Molloy.

"The fundamental issue is that we're so close to wolf recovery in the Northern Rockies and close to a success story. But the Bush Administration seems intent on reversing that," Willcox said. "We're spitting distance from recovery and now we'll be moving in the wrong direction."

The conservation groups are concerned that more than half of the wolf population could be killed under this regulation, even while being protected by the Endangered Species Act. They point to statements made by officials in Idaho and Wyoming that encourage lowering the number of wolves in those states.

Ed Bangs, wolf recovery coordinator for the U.S. Fish and Wildlife Service, said he wasn't surprised by the lawsuit being filed, but was dismayed at its content.

"I was kind of disappointed at a lot of the stuff in there," Bangs said. "This will not allow hundreds of wolves to be killed, and we don't think it will affect the wolf population.

"I think they're tuning the crowd up for delisting; they're just kind of rallying the troops with a lot of rhetoric."

Montana officials say they have no intention at this time of implementing the rule -- in part because they're meeting later this month to consider instituting a wolf-hunting season due to the success of the wolf re-introduction, begun in 1995, and they think the hunting season will keep wolf numbers in check.

Gray wolves had roamed in the Rockies but were put on the Endangered Species list in 1973 after being hunted to near extinction in the lower 48 states. More than 1,500 gray wolves now populate the Northern Rockies, with 89 breeding pairs.

That far exceeds the recovery goal of 300 wolves and 30 breeding pairs, so the FWS is considering the species removal from federal protection by the end of February. In fact, federal officials are so pleased by the species' recovery that since 2004 they've had Montana and Idaho replace the FWS as the head of wolf management programs in those states. Wyoming's wolf management plan only recently was adopted.

Montana alone is home to about 375 wolves and 40 breeding pairs, well above the minimum population requirements of 10 breeding pairs and 100 wolves.

The new rule allows wolves to be shot if they're attacking stock animals or dogs, or if they are having a "major impact" on deer, elk or moose populations.

Unveiled in the federal register Monday, the regulation is supposed to go into effect Feb. 28 after a 30-day "cooling off" period. It would remain in effect only until wolves are taken off the list of endangered species; but even if the federal government decides to do that this month, officials expect lawsuits to challenge that move. The new regulation provides a "safety valve "to wolf managers if the issue is tied up in court for an extended period, FWS officials said last week. Bangs said he expects the number of wolves killed under the new regulation will be fewer than what's being killed now for preying on livestock.

The special regulation is applicable only in the southern half of Montana, most of central Idaho and throughout Wyoming, but not in national parks.

Along with the NRDC, other plaintiffs in the case include the Defenders of Wildlife, the Sierra Club, the Center for Biological Diversity, The Humane Society of the United States, Jackson Hole Conservation Alliance, and Friends of the Clearwater. They're being represented by Earthjustice. Most of Montana's wolves are in western Montana and the greater Yellowstone area, but wolves have been reported in the Helena area, including on MacDonald Pass, the Elkhorns and as far east as the Big and Little Belt mountain ranges.

Reporter Eve Byron: 447-4076 or eve.byron@helenair.com