The Oriente covers about 130,000 square kilometers. Where the Pacific defines Ecuador's coast and the Andes create its Sierra, the Oriente finds its identity in rivers that flow toward the Atlantic - 4,800 kilometers east through Brazil. The Rio Napo, wider than a kilometer at some stretches, drains the Coca and Aguarico rivers before crossing into Peru and joining the Amazon near Iquitos. The Putumayo forms part of the northern border with Colombia. The Pastaza and Paute drop out of Sangay National Park in dramatic waterfalls. The rivers are the highways. They shift constantly, cutting new channels, leaving oxbow lakes where entire bends have been abandoned overnight. Without roads, most of the region can be reached only by canoe or small aircraft. The few cities that exist - Tena, Puyo, Lago Agrio, Coca - sit on riverbanks or at road heads leading down from the highlands.

The Oriente is home to several distinct indigenous nations, each with its own language, territory, and history. The Lowland Quechua inhabit the western foothills, their presence rooted in pre-Columbian migrations and Inca-era contact. The Siona and Secoya live in small communities in the northeast along the Aguarico River. The Cofan maintain territories along the Colombian border. The Huaorani hold a large reserve in central Napo province that borders and overlaps with Yasuni National Park, and within their territory the Tagaeri and Taromenane clans have chosen not to contact outsiders at all. To the south, the Shuar and Achuar occupy extensive rainforest territories between the Pastaza and the Peruvian border. Each of these peoples has spent the last half century responding to oil development, religious missions, road construction, and the fragmentation of their lands. Each has also, remarkably, retained a language and a politics that the Ecuadorian state has slowly been forced to acknowledge.

The Quijos region east of Coca was well known to the Incas, who descended from the highlands to meet lowland peoples in both trade and battle. It was also the first region east of the Andes that Spanish conquistadors penetrated. In February 1542, Francisco de Orellana - who had started upriver with Gonzalo Pizarro's expedition - became the first European to travel the full length of the Amazon, a journey that began in the Ecuadorian Oriente. February 12 is still celebrated in some jungle cities as the anniversary of the European discovery of the Amazon River. What followed was catastrophe. Smallpox and cholera reached communities that had no immunity. Within a few centuries after contact, most of the tens of thousands of indigenous inhabitants had died. The Spanish founded settlements. Jesuit missions followed, then Franciscan and Dominican orders. In the nineteenth century, Catholic Salesian missionaries established boarding schools. Illiteracy remained widespread. The demographic and cultural wound was deep, and in some places it has not healed.

Petroleum was discovered in the Ecuadorian Amazon in the 1960s. Texaco began commercial production in 1972, and the revenues quickly made the Oriente central to the national economy. Ecuador became the third-largest oil exporter in Latin America. A pipeline was built across the Andes to move crude from the eastern fields to the Pacific coast. What had been considered a stagnant backwater became, overnight, the country's most important resource zone. The costs have been distributed unequally. Oil spills have contaminated rivers that indigenous communities depend on for drinking water and fish. Roads built by oil companies opened the forest to colonists, who cleared land for cattle pasture. In 1993, 30,000 Amazonian residents filed a class-action lawsuit against Texaco - later acquired by Chevron - seeking compensation for environmental damage. The case became one of the longest-running environmental lawsuits in history. Ecuador courts awarded $9.5 billion in damages. The case remains contested and enforcement has been blocked by subsequent rulings in other jurisdictions.

Tourism in the Oriente has grown alongside the oil industry, sometimes in conflict with it. Papallacta, the hot springs complex on the road from Quito, sits at the edge of the region and gives travelers their first taste of the transition from Sierra to rainforest. Tena has become a white-water rafting and kayaking hub. Coca, at the confluence of the Napo and Payamino rivers, serves as the jumping-off point for trips deeper into Yasuni. Napo Wildlife Center, run by an indigenous community downstream from Coca, is among the newer lodges. La Selva Jungle Lodge, 100 kilometers down the Napo from Coca, has been operating since 1984 and is widely regarded as a pioneer of Ecuadorian ecotourism. Further south, Zamora sits near the entrance to Podocarpus National Park, 90 minutes by bus from Loja. The ecotourism revenue has created alliances. Indigenous communities that host lodges have gained political leverage in the resource battles that shape the region. What tourism cannot do is replace the forest itself - but it has given some of the forest a reason to remain standing.