The children come running as soon as the boat pushes onto the riverbank, mooring next to empty handmade fish traps. Greg Carr is at the front of the group of visitors clambering ashore. He lifts one child into the air, makes a face at another and greets adults with backslapping familiarity. Carr, an eager American with khaki pants and a Boy Scout's smile, has spent a lot of time in Mozambican villages like this one over the past three years, wooing officials and local elders alike in the hot, red dust.

Carr's smile broadens when he sees Paulo Majacunene, who oversees this district. The tech multimillionaire turned philanthropist needs Majacunene to help him make a deal with these villagers. Carr has risked millions of dollars in an effort to revive a national park across the river, a once-heralded place of sweeping savannas and velvety green wetlands called Gorongosa. He believes a restored park will lift this beleaguered region out of poverty. And he believes his success depends on the help of this village, Vinho, and others like it.

Vinho is a subsistence farming community of some 280 adults and twice as many children, one of 15 villages along Gorongosa's borders. It has a school that goes through the fifth grade and a water pump that teenage girls use to fill plastic jugs as they jostle babies tied to their backs. As Carr and Vinho's leaders settle into wooden chairs shaded by a blue plastic tarp, the villagers gather.

Majacunene speaks first. He tells the crowd that when the Carr Foundation restores Gorongosa, there will be new jobs, health clinics and money for Vinho. But the community needs to help, Majacunene says. No more setting fires. No more killing animals. Everyone nods. He leads a series of cheers, thrusting his fist into the air.

"Viva Gorongosa Park!" he yells in Portuguese.

"Viva!" the crowd answers.

"Down with poaching!" he yells.

"Down!" echoes the crowd.

Carr, who understands some Portuguese, beams.

After the meeting, Roberto Zolho, Gorongosa's warden, tells Carr that the people of Vinho are setting many of the fires in the park, which clear land for farming but devastate the ecology. Carr smiles the wry smile that seems to appear when something strikes him as particularly absurd.

"Well, we're starting," he says. "You know, it starts somewhere."

What Carr has embarked upon is one of the largest individual commitments in the history of conservation in Africa. To restore Gorongosa National Park, he has pledged as much as $40 million over 30 years, an almost unheard-of time frame in a field where most donors—governments and nonprofit organizations alike—make grants for four or five years at most. He also plans one of the largest animal reintroduction efforts on the continent and hopes to answer one of the most debated questions in conservation today: how to boost development without destroying the environment.

His efforts come against a backdrop of worldwide biodiversity loss, which is at its worst in developing regions such as sub-Saharan Africa, where conflict and poverty accelerate natural resource destruction. Last year, the World Conservation Union reported that 40 percent of the species the group assesses are under threat of extinction.

Gorongosa, Carr believes, will change all that.

The park was once one of the most treasured in all of Africa, 1,525 square miles of well-watered terrain with one of the highest concentrations of large mammals on the continent—thousands of wildebeest, zebra and waterbuck, and even denser herds of buffalo and elephant than on the fabled Serengeti Plain. In the 1960s and '70s, movie stars, astronauts and other celebrities vacationed in Gorongosa; tourists arrived by the busload. Tippi Hedren, who starred in Alfred Hitchcock's The Birds, was inspired by Gorongosa's lions to build her own exotic cat preserve outside Los Angeles. Astronaut Charles Duke told his safari guide that visiting Gorongosa was as thrilling as landing on the moon.

"They called it the jewel of Mozambique," says Frank Merry, a visiting scientist at the Woods Hole Research Center, which has received a grant from the U.S. National Science Foundation to study Carr's project. "You've got an iconic resource there....In the U.S., you might think of Yellowstone."

But all of that was before Mozambique's 16-year civil war, which erupted soon after the country won independence from Portugal and set up a socialist, single-party government in 1975. As was common across post-independence Africa, antigovernment forces took refuge in national parks, a ready source of hidden shelter and food. They set up headquarters just outside Gorongosa, and the park itself became a battlefield: land mines were planted, the main camp was shelled and the animals were slaughtered.

"There were government forces, you had the rebel force, you had displaced people—they all used the park," says Zolho, the current warden, who was a ranger in Gorongosa when the rebels attacked. "We closed the park in '83 because it was impossible."

Outside the park, government soldiers forced villagers into towns or "communal villages" dozens of miles away, often along the main road linking Zimbabwe to Mozambique's port of Beira. It was a traumatic move for people who had spiritual connections to the land and for families accustomed to living at some remove from one another.

"We ran away because we heard the shooting, and they [rebels] started to cross to this side" of the river, says Joaquim Coronheira, the 68-year-old fumo, or chief, of Vinho. "So during the night, we were running. Kids were on our backs and everybody was running. There were many killings."

By the time the war ended, in 1992, a new constitution had already established a multiparty government and market-based economy. Villagers returned and rebuilt their thatch houses. Some moved into the park itself, setting fires to clear fertile land. Poaching increased as people snared animals to feed themselves and to sell at local bush meat markets. There were few rangers to stop them.

The park was in poor shape when Carr came upon Gorongosa in 2004. The Mozambican government had cleared many of the land mines, but the main camp, called Chitengo, was still largely in ruins. Tourists were a distant memory, as were the great animal herds; of a buffalo herd that once numbered 14,000, for example, about 50 animals remained.

"When I came along, nobody talked about it, nobody remembered it," Carr says. "And people said to me, ‘Don't bother, there's nothing there anymore.'"

But with Carr's funding, Mozambican officials say, they will restore the park, teach locals to run it and create an eco-tourism industry. Soon, they believe, improved education, health and living standards will follow. Now, they must convince the local peoples—war-scarred, impoverished and separated by language and custom—that cooperating with Carr is in their best interests.

Carr stares down at Gorongosa's savannas and wetlands, yellow fever trees and a flat, silver lake that reflects his fire engine red helicopter like a mirror. He is flying to Nhatsoco, a settlement on the slopes of Mount Gorongosa, which sits outside the park, so he can meet Samatenje, the mountain's spiritual leader. Carr wants Samatenje to bless the restoration project and persuade villagers to stop cutting down trees.

Trees are crucial to the ecological health of the mountain, an oval massif 18 miles long and as high as 6,100 feet at the southern end of the Great Rift Valley. When warm air from the Indian Ocean hits the mountain, it produces abundant rains, which water the trees—some 500 species. The trees reduce solar reflection and protect against erosion with their roots and canopies; they also absorb the rains like a sponge, allowing the water to collect into rivers and hundreds of springs, which ultimately flow into the park.

Locals consider the mountain sacred, but population growth has pushed people farther up its slopes; traditional leaders say Christian missionaries and creeping modernity have undermined their bans on farming high on the mountain. In either case, clear-cutting for farmland has led to deforestation at an alarmingly quickening rate. Scientists for Carr's project estimate that unless something is done, within five years the mountain's ecosystem will degrade to a point from which it cannot recover.

The helicopter flies over sorghum fields, thatch huts and broad clearings where skinny dogs lie curled up in the dust. It begins to descend when it nears Nhatsoco. Hearing the chopper, villagers gather, about 400 of them forming a kaleidoscope of colorful scarves and clothing, faces lifted toward the sky. As the helicopter lands, they turn away, shielding their eyes from the dust and twigs kicked up by the rotors. But when the dust settles, many glare at Carr and his team, exiting the helicopter. Then a commotion erupts some yards away—the villagers point excitedly at a snake that has forced its way out of the hard-packed dirt.

They believe the snake is an unhappy ancestor. Then someone tells Carr that red, the helicopter's color, represents angry spirits. "There's all this interpretation that now we are not welcome," says Zolho, the warden. The people of Nhatsoco believe strongly in the spirit world. ("You were pretty much a flying bad omen," says Christy Schuetze, an anthropology graduate student at the University of Pennsylvania.)

Apologies and negotiations ensue: some of the Mozambicans with Carr speak to the village elders; the villagers eventually agree to guide Carr to Samatenje. After a hike of a few miles, the group arrives at dusk at a small compound of thatch huts, one of which contains Samatenje. (It is said he rarely leaves it.) The visitors seat themselves on grass mats outside the holy man's hut, where they speak to him through a dreadlocked acolyte.

Samatenje is angry, the acolyte says through a translator; the snake and the red helicopter have upset him, and besides, Carr and his group should have paused longer before entering the compound. Not only that, but a man accompanying Carr—the area's regulo, or leader—is wearing the wrong clothes. The acolyte tells the regulo to go into a maize field to change clothes and apologize to the ancestors.

Then he says Samatenje realizes that the visitors did not intend to offend; they were just given bad advice.

Carr leans back on his grass mat and gives a short laugh. Well, he muses, this is more civil than the community meetings he went to back in Cambridge, Massachusetts, while he was building his foundation's headquarters. His Mozambican contacts had coached him on many practices—he had brought black and white cloths for Samatenje's ceremony and traditional gifts of wine and tobacco—but customs differ even between nearby communities.

Samatenje talks with some local leaders. Ultimately, the word comes back: there will be no blessing.

It is dark by the time Carr's group boards the helicopter. "Maybe this is good," Carr says. "When Samatenje finally gives his blessing, it will carry more weight." Carr talks about the regulo who was made to change his clothes, a man he had only met today. "Maybe this is an opening," Carr says, a chance to get to know him better and enlist his support.

At first glance, Carr, 47 and single, seems a better fit for Cambridge's Harvard Square than this remote patch of Africa. He is partial to khakis and battered loafers and is rarely separated from his laptop. His open face brightens when he talks about his native Idaho. He says "Wow!" a lot.

He grew up in Idaho Falls, the youngest of seven children. His father was a surgeon, his mother a homemaker. As a child, he says, he played in the potato fields and spent a lot of time reading. He liked dreaming up mini-societies, trying to figure out how people could survive in a bubble on Mars, or under the ocean, or in a besieged castle. In the sixth grade he wrote a paper about the number of caribou a tribe of imaginary island dwellers could eat each year without damaging their environment.

Carr was 16 when Mozambique became independent, in 1975. He was reading Darwin's Origin of Species at the time. "That was a transformative experience," he says, one that inspired a "lifelong love of biology." Yet when he followed his siblings to Utah State University, Carr majored in history. He embraced the concept of laws higher than kings, and rights higher than laws. "The idea that every human on earth should have basic human rights—I became really excited about that idea," he says.

After graduating first in his class, he enrolled in a master's program at Harvard's Kennedy School of Government, en route, he then thought, toward getting a PhD. (Indeed, Harvard accepted him into its doctoral program in linguistics.) But while at the Kennedy School studying the ongoing breakup of AT&T, Carr realized that the Ma Bell divestiture would mean opportunities—that there was money to be made from telecommunication services. "I had the idea at 25 that if I made a lot of money," he says, "then I could do whatever I wanted."

In the spring of 1986, while finishing his master's degree, Carr maxed out his credit cards to start a company with Scott Jones, a 25-year-old scientist at an MIT lab, to provide voice-mail services to the emerging Baby Bells. The pair called their new company Boston Technology; after four years it was the nation's number one voice-mail provider to the telephone companies.

Don Picard, one of the first employees Carr and Jones hired, recalls that the company was both big on teamwork and long on self-confidence. The co-founders expected their employees to match their own obsession with work, says Picard, who was a software engineer, and they gave them equity in the company. "We're all Type A personalities," Picard says. "But I never got the sense working with them that it was about their ego. It really was, 'Look what we can do.' And it really was about 'we,' not ‘I.'"

As the company grew, Carr kept coming up with ideas to capitalize on opportunities, says Paul DeLacey, who was 46 when Carr, then 28, hired him to provide some executive experience. "The term 'consummate optimist' comes to mind," DeLacey says. Carr's rapid-fire ideas were crucial to the company's success, DeLacey says, but they also drove people crazy. Once, he says, "I picked up a voice mail from Greg, and it started with him saying, 'I have an idea.' Now, let's say it's May. I don't know whether it was my mood, or if it was just a hard week, but I just pushed 'Reply' and shouted: 'Greg, I'm still working on February's idea!'"

By the mid-1990s, Carr had moved away from day-to-day involvement with Boston Technology to serve as its chairman; he had also become chairman of Prodigy, an early Internet service provider. By the end of the decade, his personal net worth exceeded $200 million. But Carr says he still saw himself as a student of history and public policy.

He thought about marriage, he says, but figured that was something he could do later—a position he still takes. What he really wanted, he says, were two things: intellectual stimulation and adventure. So in 1998, he resigned from every one of his for-profit positions. He wanted, he says, to turn his attention back to issues that had engaged him before he made his millions—in particular, human rights.

In 1999, he created the Carr Foundation, a philanthropic organization dedicated to the environment, the arts and human rights. After an Idaho court awarded the headquarters of the Aryan Nations to a woman and her son attacked by the neo-Nazi organization, Carr bought the property from the woman and donated it to North Idaho College, which turned it into a peace park. He started the Market Theater in Harvard Square, a venture he says was in the Greek tradition of using theater to explore humanity. He helped create the Museum of Idaho, focused on the state's natural and cultural history, and the Anne Frank Human Rights Memorial in Boise. He started a radio station in Afghanistan. He donated $18 million to Harvard, which used it to establish the Carr Center for Human Rights Policy.

"He is a very, very passionate man in what he believes in," says Marilyn Shuler, the former director of the Idaho Human Rights Commission. "He believes to his core in justice."

For most of these projects, say people who worked with him, Carr's style was to provide funding, hire people he trusted and step back. But as he grew more interested in Southern Africa, with its high rates of disease and poverty, he wanted to get more personally involved. In 2000, a mutual friend introduced Carr to Carlos dos Santos, the Mozambican ambassador to the United Nations, who was then trying to interest American investors in his country.

Mozambique, which is shaped like a mirror image of California but almost twice as big, is one of the poorest nations on earth. Its per capita income is about $310, according to the World Bank. Its average life expectancy is barely 40. HIV is rampant—in some regions 18 to 27 percent of the population is infected—and the infrastructure is rudimentary.

But Mozambique is also breathtakingly beautiful. There are 1,500 miles of white sand coastline, rain forests dripping with orchids, and vast savannas. Despite its poverty, Mozambique reaps praise—from the U.S. State Department, among others—for its democratic government (the president and the 250-member legislature are chosen by popular vote) and consistent economic growth.

Carr first visited the country in 2002. By late 2003, he was holding intense conversations with Mozambican officials and aid professionals in the United States. "The basic question was, What can Mozambique do to build its economy?" Carr recalls. "What could Mozambique do that would create a multibillion-dollar industry? And how do they compete with the other nations of the world?"

The answer, he came to believe, was tourism.

"I like the idea of tourism because it's a sustainable business," he says. "Extraction industries and so forth, there can come a time when it runs out, if you're mining or you're logging or whatever. And unfortunately a lot of Third World countries get caught in that trap, where the real benefits, the real added value, is going to other nations that are processing the raw materials."

In 2004, Carr returned to Mozambique in search of a place that could be nurtured into an international vacation destination. He had read about Gorongosa and asked to see it; he made a flyover of the former jewel of Mozambique. The landscape stayed with him long afterward. "Gorongosa Park stands apart from just about any place you're going to find," he says.

In October 2004, Carr signed an agreement with Mozambique's Ministry of Tourism in which he pledged $500,000 toward the park's restoration. But soon he was negotiating a new, bigger deal and assembling a team of experts on development and the environment, seeking Mozambicans and other Portuguese speakers for leading roles. In November 2005, he signed a new agreement with the ministry, in which he pledged up to $40 million over 30 years. That document outlines aspects of the renewal, ranging from ecological restoration to economic development, and gave Carr's foundation joint operating control over the park with the Mozambican government, which retains ownership.

Last year, Gorongosa Park introduced its first herd of buffalo, launched renovations on the main camp at Chitengo, began its outreach to neighboring communities and started a tree-planting program on the mountain. Its staff has increased from 100 to more than 500, doing a variety of jobs including rangers and housekeepers, and visitors increased from fewer than 1,000 in 2005 to more than 5,000 last year.

Beyond the park's borders, African wildlife experts—who are often skeptical of foreign projects—give Carr's efforts cautious praise.
"Obviously, it is going to be a long time to see if it all works," says Markus Hofmeyr, one of South Africa's top veterinarians, who has advised Carr, "but I think the tenacity and determination he's shown have been commendable."

Carr now spends about every other month at Gorongosa, encamped at Chitengo, sleeping in a tent, one of the camp's restored concrete bungalows or the back of a pickup truck. Along with the park's communications, business and scientific activities, he also oversees its community relations. Which means going from one community to another, explaining the concept of eco-tourism (including a return trip to Nhatsoco, where Samatenje finally blessed the project). Instead of mzungu, the Swahili term for white person that sticks to most Caucasian visitors, some of the locals now call him "Senhor Greg." And so far, the "consummate optimist" remains upbeat.

A few days after his disappointment at Nhatsoco, Carr and some others from the Gorongosa project pay a visit to Sadjungira, the community led by the regulo who had been made to change his clothes. His name is Marcelino Manuel.

Although Sadjungira is less isolated than Nhatsoco, guests are nevertheless rare. The villagers' main experience with white people came during the civil war, when the governments of South Africa and Rhodesia sent troops to help the Mozambican rebels.

At a village meeting called in a clearing, men and women sitting separately face a row of wooden chairs set up in the dirt for Carr and his party. Carr introduces himself and talks about how foreigners will someday pay to walk near Sadjungira. "We recognize this mountain belongs to you," he tells the crowd. "We will not be asking you to move. We respect the fact that this is your land, and we are just visitors."

An older man rises to say that there have been whites here before, and for all their talk they have always brought trouble. A second man says that even if Carr is sincere in his promises, his sons or grandsons might not uphold the bargain.

"We need to trust each other," Carr responds. "But I realize that we need to build trust."

While the translator struggles to find the right word for "trust," a local administrator pitches in.

"A man, if he wants to be married, he has to find a woman," he tells the crowd. "First he has to start talking with her—they're not going to go to bed together the first night."

The crowd murmurs but seems unconvinced. Then Samuel Antonio, a former soldier, stands up, bows to the officials and turns to the crowd.

"You say you don't want this mzungu?" Antonio says in Sena, the local language. "Don't you want to be employed? Don't you want a job?" He makes a joke about local leaders taking public money for themselves, and some of the villagers giggle. But when he returns to the subject of jobs, they cheer.

The regulo, who has been sitting silently, now stands up and tells Carr that he will conduct a ceremony for the park.

The meeting is over, and Carr, Manuel and representatives from both sides stand up and walk to a roofless round thatch hut. Carr and a staff member enter with some village leaders and take seats on the dirt. They all start clapping with cupped hands, summoning ancestors. A spiritual leader mixes a potion and pours some on the ground.

When the ceremony ends, Carr and his team walk back to the red helicopter and climb inside. The chopper lifts off, and Carr looks down at the villagers below. They wave, until the dust and wind force them to turn away.

Journalist Stephanie Hanes and photographer Jeffrey Barbee are based in South Africa. This story was produced in collaboration with the Pulitzer Center on Crisis Reporting as part of its project about the environment and human conflict in Africa.