YELLOWSTONE NATIONAL PARK - The wolves are back from a hunt, bedding in the tall grass of the Lamar Valley.

"So that's the alpha male, 480. Two black pups, they're trying to get a regurgitation. . . . Black pup is approaching. . . . Two gray pups are bedding. . . . The black male has bedded to the left. . . . We have a black coming in carrying something. . . . This may be a grouse."

Rick McIntyre, a soft-spoken park employee, narrates into a tape recorder as he observes the Druid Peak pack. This pack is thriving, unlike the Slough Creek wolves farther down the valley. Druid Peak wolves killed the Slough Creek beta female one day recently in sight of the wolf-watchers. Three days later, the Slough Creek alpha female turned up dead, possibly killed by other females in her own pack.

This is wild stuff, on display for anyone with a viewing scope and a willingness to stand in the cold on the windswept hill that overlooks the glacier-carved valley. Yellowstone rangers say this is the best place on Earth to watch wolves in the wild.

But 13 years after being reintroduced to Yellowstone, they remain polarizing animals, generating endless controversy and furious litigation.

On Friday, the U.S. Fish and Wildlife Service took steps to revive a 2007 proposal to remove the gray wolf of the northern Rockies from the Endangered Species List. Environmentalists howled, calling it a last-gasp effort by the Bush administration to delist wolves.

The Fish and Wildlife Service had officially delisted the wolves in March, and afterward wildlife officials in Wyoming, Idaho and Montana developed management plans that included hunting seasons. In Wyoming, anyone could shoot a wolf at any time in most of the state.

A coalition of conservation groups sued in federal court. In July, U.S. District Judge Donald Molloy issued an injunction that put the wolves back on the endangered list.

Now Fish and Wildlife is reopening its plan for public comment, making clear that it believes the wolves have recovered sufficiently to allow the states to take over their management. Further litigation is a certainty.

"All wolf stuff will always be in court," says Ed Bangs, the agency's wolf recovery coordinator. Taking the long view, he says that for thousands of years, wolves have been both romanticized and demonized. "Wolf stuff has nothing to do with reality; it's all about symbolism."

The wolves are fecund - the bunny rabbits of the predator world.

But for every 100 wolves at least six months of age, only 74 will live through the year, Bangs says. Of those that will not, 10 will be killed by government agencies because they attacked livestock. Another 10 will be killed illegally. Another three will die accidentally - struck by a car, for example. And three will die from natural threats, including being killed by other wolves.

Despite the perils of wolf life, they have proved robust, growing in number by an average of 24 percent a year. Last winter, Bangs says, there were 1,513 wolves in the northern Rockies. But the population has dropped this year, and there will probably be about 1,450 come winter.

"We're losing a lot of pups this year. I can't tell you why," says Doug Smith, who leads Yellowstone's gray wolf restoration project. Canine diseases may be partly to blame. Diseases such as distemper and parvovirus can spread between dogs and wolves.

Smith also suspects that there's an element of self-regulation of population. Yellowstone is now dense with wolves - 171 of them spread among 11 packs. (The larger Yellowstone ecosystem has about 350 wolves.)

"At some point wolves control their own numbers through killing one another," Smith says.

They've now spread far from the national park. Ranchers don't want them around. Hunters see them as competition for moose and elk.

"We was doing fine without 'em," says Gerry Endecott, a ranch manager south of Jackson, Wyo. "In this day and age, it just can't go back to where it was a hundred years ago. If you go back a hundred years, you have to get rid of Jackson and all the people."

Enthusiasts cluster along the road through the Lamar Valley, gazing through spotting scopes, recording data and communicating by walkie-talkie with watchers elsewhere in the park. According to McIntyre, the park employee, the last day when no one saw any wolves in Yellowstone was Feb. 8, 2001.

They know the wolves individually. They know which packs are robust, which are weak, which have lots of pups and which have none.

The first glimpse of a wolf in the wild has driven some visitors to tears, McIntyre says.

Justin Hill, from Rapid City, S.D., drove nine hours to get here: "They're mysterious. You really can't go anywhere else in the U.S. to see them."

"We need something to control the elk and buffalo," says Don O'Neil, of Butte, Mont., as he peers through his viewing scope.

Why does he love the wolves so much?

"The sheer wildness of it. This is something we haven't had for a while. Wolves are wild."