The news, which came to me in a cryptic telephone call one day this past February, was electrifying: the ivory-billed woodpecker, mourned as extinct for more than 60 years, had been found in the swamp forests of eastern Arkansas. I was being asked to accompany a search party that was conducting its work in extraordinary secrecy. For long moments, I forgot to breathe; for the next two nights, the excitement and awe kept me wide awake.

Any birder would have been thrilled, but I've long had a special interest in "ghost species," creatures of such surpassing rarity that we cannot say whether they are alive or extinct. I've chased the fading trail of these almost mythical animals from the mountains of Tasmania to the jungles of Brazil. Still, the ivory-bill had always exerted the strongest pull—and engendered the greatest heartache.

We who love wild America, who feel a personal grief over the spectacles we'll never see—prairies awash with millions of bison, flocks of passenger pigeons whose wings roared like hurricanes, the green-and-yellow shock of Carolina parakeets whirling through an Illinois woodland—had always counted the ivory-bill as one of the heaviest losses. Never merely a bird, the great woodpecker, with its black-and-white wings and the male's scarlet crest, was an icon of the immense swamp forest wilderness that stretched from Nashville to New Orleans, east to Florida, and up to the Carolinas. One folk name for the animal was the "Lord God" bird, because, the story goes, a person seeing an ivory-bill fly by on its two-and-a-half-foot wingspan often gasped, "Lord God, what a bird!"

The ivory-bill's forest habitat fell under the blades of loggers almost from the earliest days of colonization, but the timbering reached a frenzy from the late 1880s until World War II. The bird became synonymous with extinction, a haunting reminder of what a culture may lose when it squanders its natural wealth. Like a dying flame, the great woodpecker flickered several times; it was given up for extinct in the 1920s before a pair were rediscovered in Florida, only to be shot by specimen collectors. It was again consigned to extinction, and again found, in the 1930s in Louisiana.

That small population, at most just seven pairs in the 120 square miles of old-growth forest known as the Singer Tract, became the focus of scientific study and a ferocious conservation effort, even as the loggers of the Chicago Mill and Lumber Company cut deeper and deeper into the swamps. In 1943, Chicago Mill brushed aside pleas from four Southern governors, several federal agencies and the National Audubon Society that these last woods be saved as a refuge. ("We are just money grubbers," the company’s chairman said by way of explanation.) By 1944 the Singer Tract was becoming a wasteland, its giant sweet gums cut to make tea boxes for the British, and the last ivory-bill, a female, had vanished. The guttering candle, it seemed, had gone out.

Only rumors were left. Several ornithologists claimed to have seen the bird in Florida and Georgia in the 1950s, though without documentation, and one naturalist made a tape-recording of what he said was the animal's weird kent-kent calls in East Texas in the late 1960s. Two photographs from the Atchafalaya Basin in Louisiana surfaced in 1971, and while one respected ornithologist thought they were authentic, other experts derided them as a hoax. The Cuban ivory-bill, a distinct subspecies, was rediscovered in the 1980s, then disappeared again. Most experts dismissed the periodic ivory-bill reports in the United States as mistaken sightings of its widespread but smaller cousin, the pileated woodpecker. On those occasions when a sighting was followed up, including a well-outfitted, month-long search by a six-person team in Louisiana in 2002, nothing came of them.

A few days after learning of the bird's survival, I was deep in the Cache River National Wildlife Refuge, part of the 550,000-acre swamp forest known as the Big Woods, which runs 130 miles along Arkansas' Mississippi Delta. Sunlight streamed through the winter—bare canopies of the tupelos and cypresses. Some of the trees were old behemoths that had escaped the ax, but most were second-growth, well on their way to maturity. Wood ducks lifted off the river in little explosions of spray, and beavers slapped their tails against the water in alarm.

I accompanied a lean, bearded man named Gene Sparling, who had been paddling through this remote part of the Cache a year earlier when a huge woodpecker flew out of the woods. Sparling, an experienced outdoorsman and birder from Hot Springs, knew instantly what it was, but says his mind kept balking at the enormousness of it: "'It's an ivory-billed woodpecker,' I thought. 'But they're extinct. You can't see an extinct bird. But it's an ivory-bill.' My mind just got stuck in this loop."

This is where most ivory-bill stories end; someone is certain he's seen one, but there are no witnesses, no photographs, no proof. This time was different. Two weeks later, Sparling was back, leading Tim Gallagher, of Cornell University's Lab of Ornithology, and Bobby Harrison, a photography professor from Alabama, who had been to Arkansas shortly before to check out earlier rumors. As Gallagher and Harrison paddled to the site of Sparling's encounter, an ivory-bill flapped out of the trees. They pointed and shouted; the woodpecker flared off and disappeared into the woods. Harrison, who had been searching for the ivory-bill for years, broke down in tears. Telling me the story a year later, he did so again.

Within weeks, one of the most intensive and secretive wildlife searches in history was under way, led by the Cornell Lab and the Arkansas chapter of the Nature Conservancy. More than 50 biologists took to canoes and kayaks, looked down from aircraft, or perched atop an 80-foot boom crane along the edge of the swamp. They hunched under camouflage netting in small blinds, and seeded the woods with automatic cameras and high-tech audio-recording devices.

For 14 months, the crew labored in often appalling conditions—winter's deep, bone-damp cold, and summer's heat, stifling humidity, swarming bugs and venomous cottonmouths. The searchers' families, in some cases even their spouses, knew nothing of the mission. A three-page memo, issued to each team member, advised how to deflect interest and quash rumors without actually lying. Over predawn coffee or late evening meals in local diners—anywhere other than the team's two base camps—mud-splashed crew members referred only to "the bird" or its code name, "Elvis." If anyone asked, they were simply doing a major biological inventory of the Big Woods.

My role in the drama was a minor one. The Nature Conservancy had hired me to document the search by writing an article for its magazine timed to coincide with the announcement of the bird's discovery. Although I'm now free to tell the story elsewhere, at the time I was constrained by the same pledge of secrecy as the rest of the crew. Everyone realized that if word leaked out, birders would stampede to the forest, hoping to add the woodpecker to their life lists, and greatly complicate the mission. They also knew that skeptics would demand ironclad proof in the form of photographs or recordings.

The secrecy also allowed the Nature Conservancy and Cornell to raise nearly $10 million and quietly buy up ivory-bill habitat, adding to the more than 120,000 acres of the Big Woods that the conservancy had already protected over the previous two decades. (The immense forest, about half of it now preserved as federal or state wildlife refuges, is also home to black bears and the world's largest wintering population of mallards.)

Getting proof of the ivory-bill's existence was harder than anyone expected. All told, team members glimpsed the bird fewer than two dozen times. (I wish I could say one of those glimpses was mine, but Elvis eluded me.) They made recordings of what sounded like the unique double-rap drumming of an ivory-bill, but pileated woodpeckers may, on rare occasions, make similar sounds. Likewise, the kent-kent calls caught on the automated recording units may have been an ivory-bill—or may have been an unusual blue jay call.

The clincher was a video made in April 2004 by David Luneau, a professor of electronics at the University of Arkansas and a member of the Big Woods search team. Luneau took me, moving silently in a canoe rigged with an electric trolling motor, to the spot where he and his brother-in-law got just three or four seconds of video as the ivory-bill flew away. Still, it was enough to clearly show the enormous patches of white on the rear half of the wings and bands of white on the back—proof that this was no mere pileated woodpecker.

Even after I had spent days in the forest, canoeing with team members or sitting quietly alone on an observation platform, listening to the whooping of barred owls, I sometimes found it hard to believe the object of the hunt was real. One afternoon I was paddling with Martjan Lammertink, a woodpecker expert from the Cornell Lab of Ornithology, when I noticed a tupelo tree trunk with a hole the size of a dinner plate chiseled into it, wood chips floating on the brown water below. When I asked if that was an ivory-bill's work, he shook his head. "No," he said, "when an ivory-bill cuts, it's more like a"—but I missed the rest of his reply. The simple fact that he used the present tense to refer to a species synonymous with extinction short-circuited my ears.

So far, no one in Arkansas has reported seeing more than one ivory-bill, always apparently a male, always alone. Could this be the last of his kind, a cruel taste of hope before the candle goes out? Maybe, but none of those who have been chasing Elvis through the Big Woods think it likely. If the woodpecker has lasted more than 60 years without our knowledge, the chance that we've now stumbled upon its very last member is remote. The searchers have combed only a small fraction of the huge and challenging swampland, and have yet to find his core territory or nighttime roost holes. Ivory-billed woodpeckers can live up to 30 years, so at least one pair were breeding in the past two decades. The odds are that a small, highly endangered population of ivory-bills exists.

And there is another, far more potent reason for hope. I've birded all over the country, but the Big Woods area was a revelation to me—a vast, beautiful chunk of wild land. The Southern bottomland hardwood forests of flooded cypress and tupelo swamps, and the seasonally wet uplands of oak and sweet gum, were some of the continent's greatest landscapes. Their destruction was one of our great conservation tragedies. By World War II large tracts of forest were cut almost to the last stick, but they have, to a remarkable degree, risen anew from that wreckage. The trees are still relatively young compared with the 1,000-year-old monsters that once grew there. But in this part of the world trees grow fast, and some of the second-growth is now a century old.

And if the ivory-billed woodpecker has survived in the Big Woods, maybe—just maybe—it has survived elsewhere. "You know why I think there have been so many ivory-bill sightings the last few years?" Bobby Harrison asked me as our canoes drifted side by side through the Cache. "I think they're getting more common. The habitat is there, and I think the birds are too."

Rumors of ivory-bills in the Atchafalaya—at 800,000 acres, the largest bottomland hardwood swamp in the United States—have persisted since those disputed photos in 1971. People claim to have seen the bird in half a dozen or more places around the South—the Apalachicola River, Wekiva River and the Fakahatchee/Big Cypress Swamp in Florida, the Congaree Swamp in South Carolina, the Pascagoula and Yazoo rivers in Mississippi, and the Pearl River in Louisiana. If the hunt in Arkansas holds a particular lesson, it's that this is a surpassingly elusive bird, more like a will-o'-the-wisp than a living animal.

One reason previous ivory-bill sightings have been discounted is that ornithologists didn't expect the bird to be so shy. Ornithologist James Tanner studied the last known ivory-bill population in Louisiana in the 1930s and found the birds to be conspicuously noisy during the non-nesting season and rather tame in his presence. If such birds persisted, the thinking went, surely they would have been fairly easy to find. Now some experts speculate that the noisy, tame ones were all shot and only those that were wary around humans survived.

We don't yet know if there are other ivory-bills in other swamps, and for now just knowing the "Lord God" bird lives in Arkansas should be enough. But why not hope for the best? Hope suddenly doesn't seem to be in such short supply, and the Southern bottomlands, those plundered but resilient forests, suddenly seem a wilder, more complete place.