Searching for forage grass, cattle and goats sometimes wander for days along the dirt roads of Argentina’s El Impenetrable, a dry forest of thorny shrubs and hardwoods that covers 40,000 square kilometers (15,000 sq. miles) in South America’s Gran Chaco region. Tasty grass can be scarce in El Impenetrable, so named by non-indigenous travelers who struggled centuries ago to traverse its remote, often parched terrain, where summer temperatures can top 120 degrees Fahrenheit (50 Celsius). The vast woodland is the driest and least developed portion of the one-million-sq.-kilometer (386,000-sq.-mile) Gran Chaco, a semi-arid lowland of forest and savanna shared by Argentina, Paraguay and Bolivia.

The people of El Impenetrable are largely subsistence ranchers who live in widely dispersed, ramshackle dwellings. For decades some of them grazed their animals at La Fidelidad, a sprawling, 250,000-hectare (618,000-acre) ranch that straddled the border of the northern Argentine provinces of Chaco and Formosa. Well conserved because its longtime owner, a former textile entrepreneur named Manuel Roseo, did very little ranching and logging, La Fidelidad was later converted in part into Argentina’s El Impenetrable National Park—a protected area of 130,000 hectares (321,000 acres) in Chaco Province. The transition, initially at least, did not win local hearts.

“Roseo allowed us to let our animals enter his ranch,” says Jorge Luna, a subsistence rancher and father of eight children who receives no regular income other than small social-assistance payments from the government. “That’s why when it was proposed that La Fidelidad be converted into a national park and dedicated to environmental conservation, most people opposed the idea.”

Juana Galván, one of two teachers at the primary school serving families living in the area, cites another reason. “The proposal annoyed many people not only because it made it harder to graze their livestock, but also because many men in the area worked as guides for hunters who, with the permission of the [La Fidelidad] owner, entered the ranch.”

Nevertheless, over half of La Fidelidad became a national park in the course of a years-long saga that began in tragedy in 2011. That’s when Roseo, a 75-year-old widower, and his sister-in-law, Nelly Bartolomé, 73, died by suffocation in a murder-for-hire arranged by a man who was fraudulently selling off parts of the ranch. Environmental groups successfully lobbied the government of Chaco to expropriate all 150,000-hectare (370,000-acre) of the ranch located in its jurisdiction and give 130,000 hectares of it to the federal government to create a national park. In 2014, the Argentine Congress formally designated that property El Impenetrable National Park. But the saga didn’t end until 2017, when Chaco Province successfully fended off a court challenge to the expropriation that was filed by two children Roseo had fathered with his housekeeper out of wedlock. (See "Court victory in battle to open El Impenetrable National Park" —EcoAméricas, April 2017.)


The park that emerged constitutes the largest expanse of protected land in the Argentine Chaco—Argentina’s 600,000-sq.-kilometer (232,000-sq.-mile) portion of the Gran Chaco. In the Argentine Chaco, just 4% of the land has formal conservation status and a great deal has been degraded due to deforestation associated with the advance of monocrop agriculture and large-scale ranching. In pushing for the park, conservationists pointed to these facts as well as to the broader goal of safeguarding the Gran Chaco, a woodland second only in size in Latin America to the Amazon rainforest.

Since taking over the former ranch property, Argentina’s National Parks Administration (APN) has collaborated with Chaco Province and the Rewilding Argentina Foundation, an internationally funded nonprofit, in hopes of harnessing conservation to power regional development. The effort faces hurdles, including continued poaching in the park, anemic environmental-enforcement budgets and possibly overblown expectations for tourism development in such a remote, under-serviced region, but supporters of the effort see room for optimism.

“Until not very long ago, the Chaco made its living from deforestation,” says Claudio Bertonatti, a naturalist and author of the 2021 book ‘El Impenetrable and its Secrets.’ “Now, it is betting on living in harmony with the forest. This change is a turning point in the region’s environmental history and, although there’s still a lot of work to be done, the progress has been huge.”

As a first step, Rewilding Argentina is studying the ecosystem-restoration needs of the new park and has begun holding workshops with local residents on skills required to host ecotourism. The park’s landscape is quite varied in the context of the Gran Chaco dry forest. It features vast expanses of hardwoods—mainly algarrobos (Prosopis sp.) and quebrachos (Schinoposis sp.), whose name derived from the Spanish words quiebra hacha, or ax breaker—interspersed with spiny shrubs, grassy savanna, riverside gallery forests and even the occasional wetland. The variety stems from the location, an area of dry forest that is bracketed by two rivers—the Bermejo, which descends from the Bolivian Andes loaded with sediment, and the Bermejito, an arm of the Bermejo.

Currently, access to much of the park is extremely limited. There are only 130 kilometers (81 miles) of roads, all dirt, leading to Roseo’s now-moldering former residence and several other locations on the defunct ranch. Trails are lacking as well. Accessible areas, however, offer revealing glimpses of the park’s diverse fauna. Frequently seen animals include the lowland tapir (Tapirus terrestris)—at up to 300 kilos (660 pounds), South America’s largest land mammal—the endemic Chacoan peccary (Catagonus wagneri), the giant anteater (Myrmecophaga tridactyla), the maned wolf (Chrysocyon brachyurus) and the giant armadillo (Priodontes maximus).

“So far in the national park we have documented 346 bird species, 36 amphibians, 52 reptiles and 57 mammals, without counting bats, as well as over 500 insects and 460 plants,” says biologist Gerardo Cerón, who has lived in the park for four years as coordinator of a scientific station Rewilding Argentina set up on the banks of a small lake.

Rewilding Argentina is a nonprofit formerly named Conservation Land Trust, which was founded by the late U.S. entrepreneur and ecologist Douglas Tompkins as a vehicle for enormous land-conservation projects he carried out in Argentina and Chile. Property acquired by the Trust has been turned over to the Argentine and Chilean governments to permit expansion of their respective parks systems.

The solar powered scientific station in El Impenetrable was built in 2017 using massive South African-made tents pitched on wooden platforms raised a meter above the ground to minimize disturbance of the soil and wildlife. Its core mission is to chart and analyze the local ecology so APN can use that information to develop a park management plan, Cerón says. He adds: “Many species are difficult to identify and impossible to find if you don’t live here. El Impenetrable [the larger woodland that includes the park] has been studied very little in the past because this region doesn’t have big cities and has no universities.”

Cerón says his team has gained unexpected insights. “Surprisingly, we learned that because of its diverse environments, this park has healthy populations of species typically found both in moist areas, such as the black howler monkey (Alouatta caraya), and in dry areas, such as the giant armadillo,” he points out. “We even observed a giant otter [Pteronura brasiliensis] in May of 2021, a species that for years was considered extinct in Argentina.” (See "Giant otter spotted in the wild in Chaco, surprising scientists" —EcoAméricas, July 2021.)

Rewilding Argentina aims to achieve wildlife-reintroduction successes in El Impenetrable of the type it has attained in the Iberá wetlands of northeast Argentina, where it has helped reestablish animals ranging from the collared peccary (Pecari tajacu) to the jaguar (Panthera onca) in the wild. The group’s first such project in the Argentine Chaco got underway in October, when 40 red-footed tortoises (Chelonoidis carbonaria)—a species that hasn’t been seen for years in El Impenetrable—were transported from Paraguay to a facility it operates in Corrientes province. As of December, Rewilding Argentina scientists were conducting sanitary checks on the tortoises before moving them to El Impenetrable Park for release.

“We will reintroduce various species so the ecosystem is complete,” Cerón says. “The traditional conservation vision is to take care of what exists, but we believe that, in addition, one must restore what was lost because all the species serve an ecological purpose, and a woodland without all its members, although it might look beautiful, is being degraded.”

Rewilding Argentina has received APN approval to reintroduce the tortoises as well as marsh deer (Blastocerus dichotomus) at El Impenetrable Park. The guanaco (Lama guanicoe) and pampas deer (Ozotoceros bezoarticus) are among other species the group is targeting for future projects. The two deer species and guanacos disappeared from the region in the second half of the 20th century when their grasslands were taken over by introduced cattle.

A chance to lay groundwork for restoration of the jaguar, once the region’s apex predator, presented itself in September 2019, when a camera trap near the Bermejo River caught an image of a male jaguar.

“The jaguar is ecologically extinct in the Argentine Chaco,” says Cerón. “An estimated 20 individuals remain, a number that does not allow them to carry out their role as the ecosystem’s most important predator, which is to control populations of other species. We knew we had to take this opportunity.”

Rewilding personnel transported a female jaguar from its Iberá operation to El Impenetrable three months later and managed to lure the male, dubbed Qaramtá, to a corral where the pair then mated successfully. Two cubs were born in Feb. 2021 and are slated for release once they reach the age of three.

“The project in the long term calls for bringing more females so Qaramtá can mate with them and form a jaguar population nucleus in the park,” says Cerón. He adds his team also plans to bring in wild jaguars from Brazil or Paraguay, estimating the park could accommodate some 20 or 30 jaguars in all.

His group hopes to help make nature in El Impenetrable become a tourism draw as it has over the years in Brazil’s Pantanal wetlands, albeit on a smaller scale. “I hope that in 10 or 15 years tourists will travel along the river in boats and see jaguars and other animals that in the dry season come to drink water, as is the case today in the Pantanal,” he says. “Today the animals are suffering at the hands of hunters, but I dream that instead of guns there will be cameras.”

Trying what has worked
With its wildlife restoration projects and community meetings to build local ecotourism capacity, Rewilding Argentina also is working to achieve early, conservation-driven rural development gains of the type it has helped bring to the Iberá wetlands region in Corrientes Province. There, tourism in the past 15 years has grown from near zero to nearly 60,000 visitors in 2021, providing new livelihoods to many locals previously engaged in hunting and agriculture.

But El Impenetrable Park faces steep challenges in matching that success, one being to curb illegal hunting. When the land was a ranch, the owner allowed some hunting, but there was also poaching. And poaching continues despite being prohibited throughout the park, whose 130,000 hectares are overseen by just three park guards. Area residents have also continued to use the park to graze their livestock, though that is now technically illegal, too.

These problems, not only the extensive community engagement being carried out by Rewilding Argentina, might explain why the creation of the park thus far has not provoked aggressive pushback from locals. With the federal government on a tight budget amid an economic crisis, resolving them will not be easy, Juan Garibaldi, APN director for the region that includes the Argentine Chaco, acknowledged in a recent interview with EcoAméricas.

“We have many problems, principally the easy access to the park that hunters and fishers have by way of the Bermejo River,” Garibaldi said. “Very well equipped sport hunters with a lot of buying power still pay local people to guide them. There is also the hunting that local residents do on a daily basis.”

Garibaldi says he hopes that the presence of a community-operated campground inside the park on the banks of the Bermejo will deter hunters from using the river to enter the protected land. The campground, which is being developed by Rewilding Argentina, is expected to open in April of 2022.

Modest expectations
Still, the national parks agency does not see this and other forms of tourism as a socioeconomic game-changer in such a distant, underdeveloped region. Says Garibaldi: “Tourism is an important activity in places with good accessibility and services, assets that El Impenetrable does not have. We don’t believe that it [alone] will be a significant business for the region.”

For Garibaldi, ecotourism and adventure tourism must be accompanied by new forms of sustainable rural production. He says improved conservation of the park along with environmentally friendly economic activity around it could serve as a counterweight to agribusiness-driven land-use conversion in the region.

“The Chaco and its small-farmer and indigenous communities have suffered displacement and environmental deterioration due to the advance of the agricultural frontier,” he says. “We’re counting on a sustainable-production landscape outside the national park, one that ensures the survival of the communities and of biodiversity through activities such as apiculture, limited livestock and controlled forestry.”

Though Chaco provincial officials and Rewilding Argentina appear to have far higher hopes for tourism, they also recognize the need for other forms of sustainable development to improve the lot of a rural populace that is among the country’s poorest.

Climate action might be part of the picture as well, according to Jorge Capitanich, Chaco’s governor. Capitanich says provincial and national authorities are studying a plan to issue carbon bonds based on the conservation of woodlands in the region.