El Impenetrable National Park

316,000 acres/128,000 hectares
N ational park designated in 2014
Chaco Province, Argentina

After a whirlwind of coordinated activity between Argentinean conservationists, provincial officials, and the national government, El Impenetrable was added to Argentina’s national park system in 2014. Created from a large private ranch, the park’s happy birth stemmed from a tragedy, the murder of former owner Manuel Roseo in 2011 by criminals who hoped to take his property. Following his death, the province of Chaco expropriated the land and prosecuted Roseo’s killers.

The Chaco region is the second largest forest block in South America after the better-known Amazon but suffers an even higher deforestation rate. With relatively few protected areas in this ecologically vital habitat, the idea of establishing a new national park from the former Estancia La Fidelidad property was quickly and widely embraced by the public and government officials. In a model public-private collaboration, Argentine and foreign conservationists, businesses, legislators, and nongovernmental organizations all contributed to the success.


Sofia Heinonen, president of the Conservation Land Trust–Argentina, was a key architect of the park effort. Through an agreement reached with the province of Chaco, CLT has worked with the Under-Secretariat of Natural Resources from the start of the process to establish El Impenetrable. CLT has been responsible for the logistics and administrative presence in the park area since December 2012, helping to carry out wildlife monitoring, provide training, and conduct public relations with private conservation donors and the press. CLT also provided monies to perform the land valuation appraisal and a significant part of the private funds raised to compensate the former landowner’s heirs.

The biggest national park in northern Argentina, El Impenetrable offers habitat for populations of large mammals such as the puma, maned wolf, giant armadillo, tapir, giant anteater, and three species of peccaries, and it might again be home to jaguars if a population could be reestablished. Hundreds of bird species including the crowned eagle, jabiru, blue-fronted amazon, black-bodied woodpecker, Chaco chachalaca, skimmer, and rufous-fronted thornbird occupy El Impenetrable’s well-conserved native forest.


The presence of diverse environments within the park is key for its great biodiversity: it has upland woodlands of quebrachos, groups of locust trees, riparian forests, palm forests, cardón cacti forests, grasslands, and even one of the last wetlands of the region. The Teuco River, with its regular flooding and year-round flow, plays a leading role in shaping the various natural communities and supporting wildlife populations during the dry season. El Impenetrable National Park is truly a natural jewel—with exceptional wildlife habitat that expands the already excellent national park system of Argentina, and a potential engine for nature-related economic development in one of the country’s poorest regions where local native and mestizo populations may benefit from ecotourism.