How the Interoceanic Highway ushered in a new era of deforestation and social upheaval in the Amazon

Driving east from the Inca-built city of Cusco, Peru, the Interoceanic Highway cuts a dramatic path through Andean cloud forests, twisting in hairpin turns and plunging past sharp cliff walls draped in ribbons of water. The air changes as you travel from thin, crisp and dry to thick, dense and wet. After about eight hours, you finally arrive in the flat, sunbaked rain forests of Madre de Dios, a corner of the Amazon once so pristine and inaccessible its name translates to “Mother of God.” Construction on the Peruvian leg of the 1,600-mile Interoceanic Highway—which connects the Peruvian Pacific with the Brazilian Atlantic—began in 2005 and ended in 2011. Not long after, the $2 billion project became a focal point of one of Latin America’s largest corruption scandals, the Odebrecht Case, which implicated three former Peruvian presidents in accepting bribes in return for lucrative construction contracts. As a result, this frontier-busting road is often referred to as “the most corrupt highway in the world.”

Proponents of the Interoceanic Highway touted its creation to stimulate trade and transit between southeastern Peru and western Brazil. Yet, a recent study of 62 small-scale farmers and ranchers in Madre de Dios found that, so far, rather than more positive economic opportunities, it’s ushered in a new era of social upheaval and environmental destruction.

“This highway is like a case study of how to make a bad road,” explains WWF’s Meg Symington, vice president for the Amazon, who’s worked in this remote corner of Peru since the 1980s. “The highway only opened a little over a decade ago, so it’s still in people’s memory. They know how things were before—and they can see how they’ve changed.”

How this region has changed is most evident in the La Pampa sector, located in the buffer zone of Tambopata National Reserve. Here, illegal gold mines have transformed vast swaths of tropical forest into barren landscapes. Where there was once a rain forest, there is now desert. Meanwhile, the river water used to process gold is contaminated with mercury, as are its fish (a staple of the local diet). Symington says these environmental issues are compounded by social ones, including illegal drug trafficking and prostitution, which flourish in tandem with the mines.

The modern-day gold rush is but one of many threats to have emerged alongside the highway. Nearby, forests once filled with parrots and macaws have vanished to make way for fields of corn and papaya, which line the highway heading east from La Pampa. These farms don’t belong to the region’s longtime Indigenous caretakers, but rather to new arrivals who followed the highway downhill in search of land and opportunity. These migrants from Andean regions like Cusco and Ayacucho have erected makeshift settlements all along the highway and transformed the regional capital of Puerto Maldonado from a sleepy backwater into a sprawling Amazonian city.

A study of the Brazilian Amazon estimated that 95% percent of all deforestation occurred within less than one mile of a river or just over three miles of a road. Paving a major highway like this one stimulates even more roadbuilding, further fracturing the forest and shrinking the habitats of its longtime residents. Madre de Dios is of unique concern because of its geographic location at the base of 20,000-foot-high mountains. Sediment-rich rivers flowing down from the Andes give the region both higher levels of biodiversity and more nutrient-packed soils, which Symington says are easier to convert into farmlands than the nutrient-depleted soils found in other parts of the Amazon.

In the first two decades of the millennium, Madre de Dios lost some 570,815 acres—or a patch of forest nearly the size of Luxembourg—to agricultural expansion. Nowhere is this more evident than on the highway between Puerto Maldonado and Iñapari, a small ranching community on Peru’s triple border with Bolivia and Brazil, which is devoid of forest. Instead, the road here is lined in cow pastures with only a few dying Brazil nut trees (which by law cannot be cut), offering signs of the forest that once was.

“This is an area of the Amazon where climate change could have really big impacts,” explains Symington, noting that it gets less rain than the forests further north. “The dry season could get longer, temperatures could be hotter, and rainfall could drop significantly.” All of this might precipitate wildfires, which would have been improbable in the greener, colder, and wetter Madre de Dios of two decades ago. When the rainy season does come, it is more extreme with a heavy concentration of rainfall driving floodings and landslides.

Of course, the highway brought benefits for some local residents. “Up until about 15 years ago we were more or less isolated from the rest of the country,” recalls Veronica Cardozo, a rancher in Iñapari, who says it used to take two days to reach Puerto Maldonado (now, it takes three hours). “We didn’t have proper schools to study in, and we were quite limited in what we could do.” For some, the newfound connectivity has also meant lower costs for things like food and construction materials. “We’re now improving our way of life, little by little,” she adds.

Such benefits are important to consider. That’s why WWF works with policymakers across the Amazon basin, providing robust scientific information on land use and sustainable development. The goal is to ensure that projects, if truly needed, maximize benefits for isolated communities while allowing nature to thrive.

In Madre de Dios, WWF works with local communities, partner nongovernmental organizations, corporations, and governments on a stacked approach to conserving the lands now threatened by the Interoceanic Highway. This includes everything from constructing canopy bridges (so arboreal animals can cross forest roads) to collaborating with ranchers like Cardozo on more forest-friendly ranching.

“Madre de Dios is very close to my heart and is a place where WWF has a long and rich history,” says Symington. “Twenty-five years ago, it was almost 100% forest. While there are still well-protected areas—and there is great conservation work going on—it’s important to think about what the trajectory might be for the next 25 years.”