But they know much about the pale gray wolf, including the name given to her just months before she slipped out of his crosshairs. Opal.

 Half a decade and more than 400 miles later, Opal is still a suspect, still an elusive -- and expensive -- target. And the resources devoted to Opal and her Boulder Pack depict an emerging answer in the equation that includes the topography of the Northern Rockies, the perseverance of the wolf, the chasm between animal advocates and ranchers, and a government's efforts to make concessions to every side.

 The answer is simple, but not easy: Modern wolf management is testing tolerances, second-guessing existing practices and costing more money than most budgets bargained for.

 This year, federal agencies will spend more than $1 million on wolf efforts in the three recovery areas in Northwest Montana, Yellowstone Park and Central Idaho. Or, $12 million from 1973 to 2002, the year the recovery program is expected to end with the wolf's delisting as a federally protected animal.

In Northwest Montana alone, the U.S. Fish and Wildlife Service will spend about $200,000 managing 65 to 75 wolves responsible for killing an annual average of five cows and five sheep.

 The beneficiaries of all this? An uneven split between about 230 wolves and a public that -- whether awestruck or disgusted by the animal's return -- demands accountabiliy. And public meetings, newsletters and step-by-step progress reports on wolf recovery.

 "Biologically, wolves are easy to do. Socially, they're probably the most difficult animal to manage. And that's what drives up the cost," said Ed Bangs, wolf recovery coordinator for the U.S. Fish and Wildlife Service. "Most of the money we spend is on people, not wolves."

 Managing other predators that take a greater toll on livestock costs a fraction of the wolf bill, Bangs said. But then there's no shortage of coyotes, lions and black bears in the Rockies.

 "When something's really rare, it becomes more valuable. So you spend more money on it," he said.

 Wolves are the easy part, Bangs said: Biologists don't have many problems counting and monitoring an animal that stays together in a pack, reproduces consistently and sticks to a distinct range.

 TRYING TO KEEP wolves and livestock alive on the same piece of land is more difficult. And as wolf populations in some areas double every year, it's won't get any easier.

 "It used to be a lot simpler," said Carter Niemeyer, a wolf management specialist for Wildlife Services, the new name for the U.S. Agriculture Department's former Animal Damage Control. "We used to have a core group of wolves and we knew where they were. As the population grows, there can be dispersal into new areas."

 In fact, just keeping wolves alive is expensive. For now, Wildlife Services is required to give wolves a second chance: Under what's called the Interim Management Plan, they can relocate problem wolves after their first livestock kill and shoot them after the second.

 Capturing a wolf costs more than killing, Niemeyer said, and it's usually wasted money. Too often, he said, relocated wolves can't shake their habit of killing livestock.

 "All of our effort to save them and relocate them have been in vain, and we've had to go out and repeat our efforts," he said. "More and more we're looking at one strike and your out."

 Simply, federal hunters need clearance to kill the first time a wolf strikes, Niemeyer said.

 But that's the future. For now, as it did with the Boulder Pack, the government spends thousands commissioning helicopters, hauling wolves across mountains and forming hunting parties 14-men strong.

 NAMED FOR HER eyes, Opal's record dates to June 1, 1992, when Canadian wolf researchers first cornered her in the Highwood River area near Kananaskis, east of Banff.

 Biologists didn't spend too much time with her then, said Carolyn Callaghan, assistant director of the Canadian-based Wolf Awareness. Just long enough to slip a radio collar around her neck and determine the 37-kilogram female was about two years old.

 Researchers from Parks Canada and the Alberta Department of Environmental Protection tracked her until February 1993, when a rancher fingered her as the predator killing his livelihood.

 Biologists lost her after the rancher pulled the trigger. Some might have given her up for dead, but Opal was on the move, marching south. Callaghan points to instinct -- not the echo of the gunshot in Opal's ears -- as the push that urged the wolf across the border.

 "Typically in a wolf pack, if an individual wants to become a breeder, she will leave," she said.

 THE DOGS KNEW. "The night they were here, the dogs were howling. And by golly, they sounded more like wolves than dogs. So they must have known something was around."

 Earlier this month, the Deer Lodge-area rancher was readying his calves for winter. Friends and neighbors he summoned for a morning of hard work formed a quick-moving assembly line; each calf felt the attention of several hands and at least three needles.

 The vaccinations protected the yearlings from a range of threats -- bovine rhinotracheitis, parainfluenza, pasteurella, haemolytica bacterin, clostridium.

 But inoculations were powerless early this year. The January morning after his dogs howled, the rancher woke up to the bloody remains of seven calves. Two were within view of his house, he found the rest over a rise only about an eighth of a mile away.

 The young angus calves had been mauled -- their throats ripped open -- but their killers didn't stick around for much of meal. Tracks in the snow and mud and manure pointed to wolves.

 "They didn't eat very much of them," the rancher said. "Niemeyer said that it looked to him like this was a training mission, that the old ones were teaching the young ones how to kill."

 The rancher, whose home overlooks a long, straight stretch of Interstate 90, didn't want his name used. He didn't want the type of attention -- especially by what he called Eastern do-gooders -- that wolf activity could attract to his yard.

 Wolves aren't a popular subject when they're killing your cows. A neighboring ranch, a larger operation whose owners live several states away, was even more wary. "We have nothing to say about that," said the woman who answered the phone before hanging up abruptly.

 THE BOULDER PACK was suspected. Though other packs were relocated by human hands to areas farther south -- in Idaho and at Yellowstone -- the Boulder Pack was among a handful of groups that moved through Montana on their own.

 This fact alone should win the wolves praise from their new neighbors, said Tom Skeele, director of the wolf-friendly Predator Project.

 Certainly, longtime Montanans can identify with these packs, he said. "They have the respect of the people because they made it on their own," he said. "They're better off because they have a survival instinct, they ran the gauntlet. And the goddamn government didn't shove them down our throats."

 The Deer Lodge-area rancher might have agreed before he lost calves. "I guess there's a place in the world for everything," he said. "I don't have anything against them if they don't come around killing livestock."

 Still, violence punctuated the relationships between the Boulder Pack and its neighbors. The U.S. Fish and Wildlife Service can trace the pack back several years, though its first verified livestock kill came in 1995, when the former Animal Damage Control verified a Basin-area calf died at the jaws of a wolf.

 Before the year was over, two more calves were verified as wolf depredations.

 Federal biologists responded by capturing five wolves from the Boulder Pack, two adults and three pups. The adults were sent to Glacier National Park, where one died of starvation; the pups were fitted with radio collars and released.

 They didn't live long. A month later, officials discovered one dead from a gunshot. Then they found the second's empty collar. "The third pup kind of blipped off the screen," said Joe Fontaine, Montana wolf recovery leader for the U.S. Fish and Wildlife Service. "It was assumed to be illegally killed as well."

 THE CONFIRMED KILLING resumed in January of this year, when the Deer Lodge rancher found his seven dead calves. Days later, neighboring ranches reported two more kills.

 This time, Wildlife Services responded with a mix of captures and killing of its own. In January, federal hunters shot four large pups spotted a few miles east from where the calves were killed, Fontaine said.

 After more calves died in June, Niemeyer captured the alpha female, intending to fit her with a radio collar so they could follow the pack. She was already wearing one.

 The wolf was sedated, Fontaine said, and officials removed the long-dead collar. They traced it to Alberta, and learned the wolf they were hunting was named Opal.

 Fish and Wildlife officials can't say when she first joined the pack, but suspected she carried her taste for beef across the border.

 Even with a new collar giving away the pack's movements, wildlife officials spent most of June missing their mark. After a ground hunt by 14 men turned up nothing, they turned to urine-scented traps. Nothing. His staff had no reason to feel rushed, Niemeyer said.

 "It did drag out a long time. But it really wasn't a burning issue with us as long as there wasn't additional livestock being killed," he said. Federal hunters did feel the weight of public scrutiny, which demanded amnesty for the pack's pups. If his men had been given a green light to simply eradicate the wolves, the Boulder Pack would be history.

"If we were in a lethal mode, where we were just required to get the wolves, it would have been a very short and sweet method," he said. "The real problem came when the public became aware of the pups. We had to modify our efforts to assure the public we weren't going to kill the adults and leave the pups to die."

 Taking to the air to capture wolf pups requires two to three hours of a joint effort of a spotting plane and a helicopter. The helicopter costs between $400 and $600 per hour, Niemeyer said. The plane adds another $100 to the bill. Wildlife Services flew at least five times in search of the Boulder Pack, he said.

 "It's expensive but it's usually quick compared to spending days and weeks setting trap lines and having to check traps daily," he said. In mid-July, Niemeyer caught three pups and sent them to an Idaho holding pen, where two were apparently killed by another wolf. Three weeks later, they killed two more adults and captured another pup. Opal slipped into nearby trees with her remaining two pups.

 OPAL WILL RETURN to Canada in pieces. The same agencies that first collared her requested her skull and tissue samples, Callaghan said. Niemeyer -- or another Wildlife Services staffer -- will shoot her when hunting seasons ebbs.

The Deer Lodge-area rancher was paid about $350 per head by Defenders of Wildlife, he said. His dead calves were proof, to him, that wolves and livestock don't mix. "They shouldn't have never brought them back," he said. "If an old wolf is hungry, he's going to take the easiest thing to kill."

 Niemeyer defended the cost of management. "The way the program is designed, I'd say it's expensive," he said. "But my point is, from a professional standpoint ... most wolf experts have retired and died. It's a science we're relearning."

 But he'll push, he said, for a change in policy. With the flexibility to kill problem wolves on the first offense, he said, his office can save the time and money it spends capturing wolves only to watch them kill again.

 And Bangs will prepare for what he believes will be the real dispute -- the expected delisting of wolves and the possible public wolf hunting season that could follow.

 A showdown seems inevitable: With Minnesota's thriving wolf population crowding itself out of the timbered lake country in the north, more and more packs are pushing the edge of the range.

 And they're slinking into the wide-open agricultural lands that roll toward that state's south and west horizons.

 Their hunger -- fueled, in part, by deer numbers bruised from a pair of harsh winters -- is leading them to more livestock than ever before. And these bloody barnyard confrontations are leading federal trappers to their busiest year yet.

 As of last week, agents for Wildlife Services -- a new name for the U.S. Department of Agriculture's old Animal Damage Control -- had killed 244 wolves in Minnesota.

 "As wolves increase and expand, you have to cover a bigger work area each year," said Bill Paul, a Grand Rapids-based district supervisor for Wildlife Services. "It's really hard to get funding. People recognize it's necessary, but it's not politically popular, to get money to kill wolves."

 He doesn't expect his job to get any easier. Though the 88 farms with verified wolf depredations represent less than 2 percent of the 8,000 operations inside Minnesota wolf territory, the animal's population is moving up and out.

 "The two things wolves need are prey and protection from humans. And they've got both of those here and they're doing very well," said Dave Schad, forest wildlife program leader for the Minnesota Department of Natural Resources.

 Though no recent hard numbers exist, Schad estimated his state's wolf population at between 2,000 and 2,500.

 Those wolves -- some of which were spotted just an hour from the Twin Cities -- might cause more problems, but they're also a sign of a fruitful recovery program. And that, too, can trigger more controversy. No longer considered endangered, Minnesota's wolves are scheduled to lose their federal protection as a threatened species in 1999, Schad said, and lobbying groups are already lining up. Deer hunters -- who compete for the same prey -- want the state to declare an open season on wolves; advocates will fight for continued protection.

 The wolf's fate will be decided in a series of public meetings, roundtable discussions and, possibly, the state legislature.

 "There's a lot of controversy surrounding wolf population in the state. Farmers, hunters are concerned. There's also a lot of support for wolves," Schad said. "This is all going to be very interesting here in the next couple of years."

 Meanwhile, some of Minnesota's wolves aren't stopping at the border: They just test the ice of the Red River before trotting across to North Dakota.

 They don't find friendly country. Though once home to wild wolves, North Dakota's predator population was effectively eliminated in the early 20th Century. Those habits seem hard to break: Federal biologists are able to confirm a half-dozen of the 40 to 50 annual reported wolf sightings, but they don't believe the state is home to a resident population.

 State and federal wildlife workers provide some of the confirmation by reading tracks; in other cases, they have a carcass of lifeless evidence to inspect.

 "We've had more than one shot by hunters mistaking them for coyotes, and we've had some controlled by ADC folks," said Mike Olson, an endangered species biologist for the U.S. Fish and Wildlife's state office in Bismarck.

And other wolves simply meet the front bumper of a fast-moving 18-wheeler, he said. On average, Olson estimated at least one wolf per year during the last decade has died in North Dakota.

 Based on the bodies they've inspected, officials believe North Dakota's wandering wolves are typically between one and two years old. They've been kicked out of the pack, and they're setting off on their own.

 Most come from Minnesota, though some venture south from Manitoba. And several years ago, a wolf from Montana met a 30-30 slug after venturing into North Dakota's western badlands during hunting season. Today, its body is on display in a Watford City school.

 With growing populations in two neighboring states, Olson thought it was just a matter of time before wolves forge a permanent home in North Dakota.

 He wouldn't say whether that's a good thing.

 "I think that wolves were certainly part of the state's history, and they aren't part of that now," Olson said. "Some would consider that unfortunate, and others would consider that fortunate. There's two sides to the wolf issue; there's no doubt about that."

 BOZEMAN -- Tom Skeele walks his wolf down a delicate path, careful to keep it somewhere on that narrow trail between martyr and marketing tool.

 Director of the Bozeman-based Predator Project, Skeele decided six years ago it would be his job to fight for wolves and bears and other animals that make a land wild.

 He couldn't have found a better salesman.

 Because Skeele discovered the wolf's real power, and it's not the animal's killing jaws or relentless tenacity. He knows the wolf, its image, is the symbol strong enough to dislodge some deep, visceral and sometimes sympathetic emotion.

 And suddenly, people -- many he's never met, many who have never glimpsed a wolf in the wild -- send money from faraway places to help Skeele help the wolf.

 "The wolf and the grizzly -- more, I think, the wolf -- are just the things that catch people's attention," he said. "There is a mystique about the wolf, more than any other predator. It may well be damn more than any other animal."