The Gran Chaco

One of Argentina’s forgotten corners, the Gran Chaco is a land of seemingly unending alluvial plains and scrubby desert. It has little in the way of dramatic scenery, no impressive historical monuments and few services for the visitor, but if you have a special interest in wildlife you will find it rewarding, provided you avoid the blistering heat of summer. In the sizeable sectors not yet cleared for agriculture, it harbours an exceptional diversity of flora and fauna, making it worth your while to break your journey for a day or two as you cross the region. Birdwatchers fare best: more than three hundred bird species have been recorded in the dry Chaco. Anglers come from all over the world in search of fish such as the dorado.

Wet Chaco scenery is mostly found near the river systems of the Río Paraguay and the Río Paraná, where the rainfall can be as high as 1200mm a year, causing heavy flooding at times. Narrow strips of jungle border the main rivers that cross the region from west to east: the Río Pilcomayo and the Río Bermejo, which, after a fairly energetic start in the Bolivian highlands, grow turgid with the heavy load of sediment they carry by the time they reach the Chaco plains. In some places they dissipate into swamps called esteros or bañados, or lagoons that can become saline in certain areas owing to high evaporation.

Rainfall diminishes the further west you travel from the Paraná and Paraguay rivers, and the habitat gradually alters into dry Chaco scenery, typified by dense thornscrub that is used to graze zebu-crossbreed cattle, but cleared in those areas where irrigation has made it possible to cultivate crops such as cotton. This zone was known to the conquistadors as El Impenetrable, less because of the thornscrub than for the lack of water, which only indigenous groups seemed to know how to overcome. Indeed, Formosa and Chaco provinces still have one of the most numerous and diverse indigenous populations in the country. These communities include the once-nomadic Toba or Komlek (Qom-lik) – part of the Guaycuru family of tribes, who mostly live on the banks of the Río Pilcomayo and in Formosa Province and make a living from manual labour and crafts such as basket-weaving and pottery – and the Wichí – part of the Matacoan language family – who still rely on hunter-gathering for their economic and cultural life but also sell beautifully woven yica bags made of a sisal-like fibre.

Best time to visit the Gran Chaco

The Gran Chaco records some of the highest temperatures anywhere in the continent from December to February, often reaching 45°C or more. At these times, the siesta becomes even more sacred and people take to drinking chilled tereré. The best times to see wildlife are in the early morning or late afternoon and the best time of year to visit is from June to September: although night frosts are not unknown in June and July, daytime temperatures generally hover in the agreeable 20–25°C bracket. Moreover, the deciduous trees lose their leaves, so you’ve more chance of seeing wildlife. The rainy season generally lasts from October to May but violent downpours are possible throughout the year. For outdoor activities arm yourself with insect repellent, sunscreen and a hat, especially in summer; and make sure you have plentiful drinking-water supplies.

Wildlife-viewing in the Chaco

The main reason for visiting the Chaco is to see its varied and fascinating wildlife. Despite the vast lists of elusive, endangered mammals given in the region’s tourist literature, though, only the very luckiest or most patient observers will see a jaguar, maned wolf, giant armadillo or mirikiná (nocturnal monkey). The surest bet for seeing any animals is to hire the services of one of the region’s few but excellent tour operators (see Tours in the Gran Chaco).

Parque Nacional Copo

In the northeast corner of Santiago del Estero Province, the Parque Nacional Copo is the best remaining chunk of prime dry Chaco left in the country and the only area of protected land in the Argentine Chaco big enough to provide a sustainable habitat for some of the region’s most threatened wildlife, including the elusive Wagner’s peccary. Giant and honey anteaters also inhabit the park, as do the threatened crowned eagle, the greater rhea and the king vulture. Frequently parched, it’s a huge expanse of approximately 1140 square kilometres, with 550 square kilometres of provincial reserve attached to the west.

Parque Nacional Río Pilcomayo

The edges of the woodland patches of the Parque Nacional Río Pilcomayo, to the north of Formosa city, can be great for glimpsing the larger mammals, including giant anteaters, honey anteaters, peccaries, deer, three types of monkey and pumas. Capybara, the two species of cayman, and even tapir live in the wetter regions of the park. Jaguars are believed to be extinct here, but the maned wolf can, very occasionally, be found – indeed, this park offers one of your best chances of seeing one. Almost three hundred species of birds have been recorded here, including the bare-faced curassow and thrush-like wren, both highly endangered in Argentina.

Complejo Ecológico Municipal (Sáenz Peña)

The Complejo Ecológico Municipal, on RN-95 near Presidente Roque Sáenz Peña, however, is really the only place for guaranteed viewing of the endangered beasts of the Chaco, including the maned wolf, jaguar, puma, tapir, honey anteater, bare-faced curassow, giant anteater and giant armadillo. This zoo fulfils an important educational role in an area where ecological consciousness is sometimes acutely lacking. Poorly funded, it nonetheless does an excellent job at rescuing, releasing or housing wounded or impounded specimens that are the victims of road traffic accidents, fires, illegal hunting and unscrupulous animal trading.

Tours in the Gran Chaco

The logistics of visiting the parks and reserves in the Gran Chaco region, and Formosa Province in particular, are complicated to say the least. Argentina’s hottest climate, poorest roads and most inaccessible terrain are likely to frustrate even the most adventurous of travellers. Signposts are erratic and wildlife lurks where you least expect it. You will certainly need a helping hand if you are to get the most out of the Chaco and you will be best off going on an organized tour with a reputable company. Aventura Formosa has extremely reliable tours run by an experienced local guide with a tremendous in-depth knowledge of the region, its geography, wildlife and culture. El Jabiru runs birdwatching trips into the Bañado de la Estrella and other trips in Formosa, including to the Parque Nacional Río Pilcomayo; English spoken.

Chaco Province

The easternmost strip of Chaco Province, along the Paraná and Paraguay rivers, is the heartland of the wet Chaco. Most of the original forests and swamps have fallen victim to agricultural developments, dedicated to the production of beef cattle and crops such as fruit, soya and sugar cane. The main highway through this region is the RN-11, which connects Santa Fe with Resistencia, the starting point for trips along the RN-16 to Parque Nacional Chaco and the interior of the province.

“El Chaco” and the Campo del Cielo meteorites

An estimated five thousand years ago a meteor shattered on impact with the earth’s upper atmosphere, sending huge chips of matter plummeting earthwards, where they fell on a 15km band of the Chaco. This cataclysmic spectacle and the subsequent fires that would have been triggered must have terrified the locals. When the Spanish arrived in South America, the Komlek called the area Pigüen Nonraltá, or “Field of the Heavens” – Campo del Cielo in Spanish. They venerated the “stones from the sky”, whose surface, when polished, reflected the sun. Mysterious legends reached Spanish ears, arousing an insatiable curiosity for anything that smacked of precious metal, and even sparking illusions of the fabled City of the Caesars, a variant of the El Dorado myth. In 1576, Hernán Mexía de Miraval struggled out here, hoping to find gold, but, instead, he found iron. The biggest expedition of all came in 1783, when the Spanish geologist and scientist Miguel Rubín de Celis led an expedition of two hundred men to find out if the Mesón de Fierro – a 3.5m-long curiosity and the most famous of the meteorites – was in fact just the tip of a vast mountain of pure iron. When they dug below, they found only dusty earth. The latitude was recorded, but since there was no way of determining its coordinate of longitude, the Mesón de Fierro was subsequently lost – it’s probable that the indigenous inhabitants reburied their “sunstone”.

The largest of the meteorites you can see today, “El Chaco”, has been reliably estimated to weigh 37,000kg, a strong contender for the second biggest in the world (the biggest, almost twice the size, is in Namibia). El Chaco and the Campo del Cielo both lie in the southwestern corner of Chaco Province, 15km south of the town of Gancedo, in the Reserva Natural Pigüen N’onaxá.


Resistencia is Chaco Province’s sprawling administrative capital, with about half a million inhabitants, and the principal gateway to the Gran Chaco. Despite its commercial importance and lack of colonial architecture, the city is a pleasant enough place; it has a feeling of spaciousness about it and is known for the outstanding friendliness of its inhabitants. The city’s self-styled nickname is “Ciudad de las Esculturas” (“City of Sculptures”), owing to over two hundred outdoor statues scattered throughout town.

Fogón de los Arrieros

Aldo Boglietti, the man behind Resistencia's sculpture project, aimed at using art to instil civic pride, also founded (in 1943) a remarkable cultural centre called the Fogón de los Arrieros, the city’s most famous attraction. Its name means “The Drovers’ Campfire”, and it’s where artists traditionally came to meet, share their particular art form and then continue their journey. You can visit during the day to look round the eclectic mix of paintings (including works by Fontana and Soldi) and sculptures left behind by visiting artists, but it’s more fun in the evening, when you can have a drink or empanada at the cosy bar. Best of all, try to catch one of the events – concerts, poetry recitals and the like – staged once or twice a week in the main salon or, weather permitting, the patio.

Top image: Maned wolf (Chrysocyon brachyurus) in Argentina © Vladimir Wrangel/Shutterstock

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Andy Turner

written by Andy Turner

updated 26.04.2021

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