A golden eagle preens in the dazzling autumn light. Elk graze damp meadows. Fiery aspens fleck slopes carpeted with spruce, fir and ponderosa pine. In remote canyons, bears and mountain lions stalk their prey.

Around it all, a strand of barbed wire punctuated by imposing signs: "POSTED: No Trespassing."

This is the Baca Ranch.

To the public, it is a paradise lost--95,000 acres of National Park-quality scenery that has been privately owned for more than a century. In scenic pullouts along Highway 4, carloads of people gaze and point and peer through binoculars at this off-limits natural wonderland.

"It's a kind of high-altitude Rocky Mountain Eden," said William deBuys, a New Mexico author and conservationist.

The ranch has been well cared for by its current owners, the Dunigan family of Abilene, Tex. But as New Mexico's urban population explodes and the canyons of the Jemez Mountains fill with weekend homes and ranchettes, the temptation to subdivide or sell the ranch has grown. Santa Fe and Albuquerque, two of the nation's fastest-growing urban areas, are within a two-hour drive.

Last month, Congress took a major step toward saving the Baca from such a fate, allocating $101 million to purchase the ranch for conversion into public land. The only remaining issue is how the government will manage the property.

"This may be the last chance to get the ranch into public ownership in a largely undisturbed state," said Dave Simon, southwest regional director for the National Parks and Conservation Association.

This is the fourth time the U.S. government has talked about buying the Baca, and the third time it has tried. In past attempts, misfortune or political strife has torpedoed the purchase.

The last time the government came close to buying the property, negotiations ended when its owner, James P. "Pat" Dunigan, suddenly died.

The first time, in the 1960s, conflicts arose over which federal land management agency would run the place. The U.S. Forest Service had a natural claim because it already owned the land surrounding the ranch. But two features made the Baca a natural for the National Park Service--incredible scenery and textbook geology.

To see what makes the Baca special, take a flight from Albuquerque to Denver. On the left side of the plane, just before it reaches cruising altitude, is the coniferous green of the Jemez Mountains, which then opens up into a sea of golden meadows.

The ranch sits in a perfect ring of mountains called the Valles caldera. A million years ago, a volcano taller than Mount Everest existed there. But a pair of colossal eruptions emptied its magma chamber, hollowing out the volcano. It collapsed into its hollow center, creating a hole more than a half-mile deep and 15 miles across. All 95,000 acres of the ranch are in that giant bowl.

Over the millennia, more hot lava has risen from below and punched through the caldera floor, creating little peaks inside the bowl. The result is a network of grassy valleys, or Valles, separated by forested peaks and ringed by the mountain wall.

"It's beautifully self-contained," said deBuys. "You can be . . . on the property and see nothing but the property."

Simon calls it "New Mexico's Yellowstone," and the Baca has all the elements of America's most famous national park, albeit on a smaller scale. There are even hot springs--signs that there is still molten magma deep beneath the caldera.

The government granted the land to its first owner, Luis Maria Cabeza de Vaca, in 1860. It was a sheep ranch for most of the early years. But by 1962, when James P. Dunigan bought the land from Frank Bond and Son Inc., cattle were being raised on the property.

There also were elk, reintroduced to the area in 1947 after decades of absence. In the 1970s, the elk population boomed, and the Dunigan family runs a lucrative hunt on the property. Hunters pay as much as $10,000 for a shot at a trophy bull.

The elk go to lower elevations for the winter. When they return in the spring, they don't have hunters to worry about, but they don't have the place to themselves, either. Five thousand steers graze the property each summer.

Some people would like to see the elk hunting end and the cattle go. But in New Mexico, where ranching is as much religion as business, not many people expect--or even want--to end hunting and grazing here.

"People persist here in ranching not because of the economics but in spite of them," said deBuys. "There's really something important about having a working relationship with land."

Sen. Pete V. Domenici (R-N.M.) agrees. In exchange for his support of the purchase, Domenici has insisted that, under public ownership, the Baca should continue to be operated as a working ranch.

The legislation calls for a board of trustees that would be required to run the ranch as a self-sufficient moneymaking enterprise, much the same way it is today. But deBuys and Simon warn that such an arrangement could open the door to overgrazing, destructive timber harvesting and generally poor land management.

While politicians, environmentalists and federal land managers debate the best way to manage the Baca Ranch, and the people of New Mexico eagerly await the day that the gates swing open, most of the people who work and play on the ranch today have mixed feelings about the impending sale.

Albert Vigil has worked on the Baca since 1992. He has devoted two summers of his life to repairing the property's perimeter fence and has lived here alone all winter as the ranch's caretaker.

Vigil grew up not far from here, in Jemez Pueblo, where the Baca's Redondo Peak is considered sacred. This summer, he took his 93-year-old grandmother for her first visit to the mountain.

As he drives his pickup along the ranch's narrow dirt roads, Vigil looks sad when it is suggested that the sale of the ranch could cost him his job.

"I don't want to leave," he says. "Because I love this place."

CAPTION: Trail horses drink from a spring on the 95,000-acre Baca Ranch, which sits in an ancient volcanic crater. The U.S. government is making another attempt to buy the New Mexico property, considered a natural treasure.