Source: Wall Street Journal
SEARCH PARTY A thatch-covered canoe heading downriver during the 2002 expedition to the Javari Valley Indigenous Land.
For the native peoples of the Amazon, the beginning of the end arrived one day early in 1500, when Spanish explorer Vicente Yáñez Pinzón eased his small ship into the mouth of the great river. The waterway was so incomprehensibly grand that Pinzón sailed 200 miles upstream before realizing he had left the ocean.
Forty-one years later, conquistadors Gonzalo Pizarro and Francisco de Orellana dared the rainforest in search of El Dorado, the fabled land of gold, only to encounter starvation and violence at the hands of the indigenous tribes. Then, beginning in the 18th century, European scientists such as Charles Marie de La Condamine and Alexander von Humboldt ventured into the Amazon, taking only measurements and specimens.
All these outsiders kept to the principal rivers, and most of Amazonia remained a vast unknown. But that began to change in the late 1800s, when the demand for rubber lured outsiders deeper into the forest, where they terrorized and enslaved the native peoples (and prompted a British diplomat to coin the expression "crime against humanity"). Early in the next century came explorers such as Teddy Roosevelt and Percy Fawcett, bent on discovering and mapping, and anthropologists such as Claude Lévi-Strauss and Napoleon Chagnon, keen to contact and study far-flung tribes.
From the start, the most dangerous baggage carried by these invaders wasn't guns or metal axes but microbes. With no resistance to European diseases, the Indian populations plummeted, and the survivors abandoned their traditional lands and fled farther into the rainforest.
In the 1970s, Brazil, which has the lion's share of the Amazon basin, began building the Trans-Amazon Highway to spur economic development. Loggers and farmers rushed in, and the ensuing 40 years have seen more destruction of the forest than the previous 500.
The people of the forest have also suffered. For much of the 20th century, Brazil sought to incorporate the tribes into mainstream society. But the rising economic tide never lifted the Indian canoes, and fresh contact with outsiders continued to kill. The government relocated some indigenous groups to more remote areas, but by the late 1980s it was clear something more was needed.
In 1987, the Department of Isolated Indians, under its founder, Sydney Possuelo, began to create and police large reserves surrounding uncontacted tribes. Though the policy was resisted by those who sought to exploit the Amazon's riches, Mr. Possuelo was tireless. "I fight for the human rights of those who do not even know that human rights exist," he said. His attempt to gauge the success of his strategy with an expedition deep into the Amazon is the subject of Scott Wallace's "The Unconquered."
Mr. Possuelo's mission penetrated the vast Javari Valley Indigenous Land, 33,000 square miles of dense forest in the Upper Amazon where aerial reconnaissance showed at least 18 uncontacted tribes. Very little is understood about these people, including what ethnic groups they belong to and what languages they speak. One mysterious band is known by neighboring Indians as the flecheiros, Portuguese for "arrow people," for their rumored mastery of that weapon and their supposed ferocity.
Unlike the anthropologists, Mr. Possuelo didn't want to study the flecheiros, since contact would only begin the process of their destruction. But he did want to know that his isolationist policy was working, and he wanted the political and financial support that such a demonstration would bring. So in summer 2002, he led his expedition into the valley to check for signs of outside encroachment and to probe the flecheiros' well-being—without making contact. Mr. Wallace, a writer for National Geographic, went along.
The expedition would consume three grueling months in some of the most dangerous territory in the world, so thickly wooded and remote that satellite phones were often useless and helicopter rescue was impossible. And so Mr. Wallace's book is above all a rousing adventure tale, told in vivid, day-by-day detail. Not only do we experience the miseries of gnats, mosquitoes and ants and the perils of snakes, caimans and jaguars, but we see how quickly one becomes inured to filthy clothes and hands and how a steady diet of monkey meat can make even electric eel seem a delicacy. No wonder Mr. Wallace shed 33 pounds over the course of the journey.
We also see the internecine scheming that can arise on a long, Conradian slog through hostile territory, especially when aggravated by the leader's erratic discipline and mercurial moods. And, as the expedition begins to encounter signs of the flecheiros—a hastily abandoned village, human figures melting into the woods—we realize the risks posed by the very people the enterprise is meant to protect: Having come to associate outsiders with danger, the flecheiros have a reputation among the other tribes for shooting their curare-tipped arrows first and asking questions later.
From all evidence, the flecheiros are thriving in their protected homeland, as are other isolated Amazon groups. But nearly 10 years after Mr. Possuelo's expedition, they are still besieged, not only by loggers and farmers but also by gold miners, oil drillers and drug traffickers, who erode the margins of the reserves. Mr. Possuelo implores: "The isolated Indians must live. They are our purest essence, out most vital impulse." But it is uncertain how much longer the native peoples, and the rainforest itself, can survive the long slide to oblivion instigated by Vicente Yáñez Pinzón half a millennium ago.