The Chaco Boreal, that immense semi-desert plain that occupies much of western Paraguay, was for a long time a no man's land: sparsely populated, hostile and of imprecise borders. In the early twentieth century, Paraguay and Bolivia disputed its sovereignty. Bolivia, which had lost its Pacific outlet in the War of the Pacific (1879-1884), coveted the Chaco as a route toward the Paraguay River and the Atlantic, and the existence of oil in the region was also suspected, which drew the interest of foreign oil companies. The tension escalated until it led to the Chaco War (1932-1935).
It was one of the bloodiest conflicts in South America in the twentieth century, with an estimated toll of more than 100,000 dead on both sides. It was fought in very harsh conditions, in a territory where thirst killed as much as bullets: water was the most precious commodity, and control of the wells and watering holes was decisive. The armies advanced and retreated through the thorny scrubland, building and contesting forts across hundreds of kilometers, many of which can still be visited today in the Central and Boreal Chaco.
The central figure on the Paraguayan side was José Félix Estigarribia, commander-in-chief who led the operations and to whom much of the Paraguayan military success is attributed. The war ended in 1935 with a situation favorable to Paraguay on the ground, later consolidated by the 1938 peace treaty, which awarded the country most of the Chaco Boreal. For his role, Estigarribia was promoted to marshal, the country's highest military rank.
On July 21, 1938, the Treaty of Peace, Friendship and Boundaries between Paraguay and Bolivia was signed in Buenos Aires, popularly known as the Peace of the Chaco. It was signed, for Paraguay, by Cecilio Báez and José Félix Estigarribia, and for Bolivia, by Eduardo Díez de Medina and Enrique Finot, under the mediation of several American countries gathered in the so-called Chaco Peace Conference.
The treaty awarded Paraguay about 75% of the disputed territory (about 247,328 km² of the 324,000 km² of the Chaco Boreal), while Bolivia kept approximately 76,672 km², including a corridor toward the Paraguay River that guaranteed it a river outlet, one of its central historical claims. The definitive and complete demarcation of the boundaries, however, was not formally closed until April 27, 2009, more than seventy years later, when the two countries signed the final boundary act within the framework of that 1938 treaty.
The peace consolidated Paraguayan sovereignty over the region and opened the era of colonization, settlement and development of the Chaco that would define the following century: the founding of new towns, the advance of the Mennonite colonies and the installation of military garrisons at strategic points like Mariscal Estigarribia.
The town of Mariscal Estigarribia was born and consolidated in close relation with the military and state presence in the Chaco, after the Chaco War. Its name honors Marshal José Félix Estigarribia, the military man who commanded the Paraguayan forces in the war and who later, in 1939, reached the presidency of the Republic, a post he held until his death in a plane crash in 1940. Naming the town after him reflects the symbolic weight the war and his figure hold in the memory of the Chaco.
Strategically located on the road that crosses the Chaco toward Bolivia, the town developed as an outpost of the colonization, defense and administration of the vast Chaco territory. The presence of the armed forces has been a permanent feature, given its border position and its logistical and strategic importance. Over time, around that nucleus a civilian population formed, dedicated to trade, services and cattle raising.
Mariscal Estigarribia thus became the urban reference of the deep Chaco: the place where, before venturing into the semi-desert immensity or crossing into Bolivia, travelers and the state presence itself find their last solid base. Its history condenses that of the modern Chaco: the war, the colonization and the effort to integrate a remote, extreme region into the country.
Between 1977 and 1986, Paraguayan military engineers built in Mariscal Estigarribia an airfield with one of the longest runways in the country, more than 3,600 meters, originally intended to boost a free-trade zone and the economic development of the northern Chaco. Today it bears the name of Dr. Luis María Argaña International Airport, in homage to the Paraguayan vice president assassinated in 1999.
Starting in June 2005, the version began to circulate, first in regional media and then international, that the United States was installing a military base at the site, within the framework of military-cooperation agreements between the two countries signed that same year. The news generated concern in several South American governments due to the site's proximity to the Bolivian border, to natural-gas reserves and to the Guaraní Aquifer. Both the government of Paraguay and that of the United States officially denied the existence of a permanent base; the spokesman for the Paraguayan Armed Forces, Colonel Elio Antonio Flores, stressed in 2005 that the runway had been built entirely by Paraguayan engineers and not by U.S. personnel.
More than a decade and a half later, the rumor of the 'Mariscal Estigarribia base' is still repeated in geopolitical analyses and press articles, though it was never confirmed. What is certain and verifiable is that the airfield remains a Paraguayan military installation, of occasional use, and that its existence —real or mythologized— is today part of the identity and the curiosity that surrounds this border town.
After the war, the Paraguayan Chaco remained a region of slow and diverse settlement. To the native indigenous communities —Chaco peoples like the Nivaclé, Ayoreo, Guaraní Ñandeva and others— and the military presence were added the Mennonite settlers, who since the 1920s had begun founding their colonies in the Central Chaco (Filadelfia, Loma Plata, Neuland), and criollo population arrived from the Eastern region. This human mosaic defines the cultural identity of the area.
The opening and improvement of the Trans-Chaco Route, which links Asunción with the Bolivian border crossing the whole Chaco, was key to integrating the region with the rest of the country and reinforced Mariscal Estigarribia's role as a transit hub. Today, along that route flow international trade with Bolivia, adventure travelers and the cattle production of the area, which has become one of the economic engines of the Central and Boreal Chaco.
At present, Mariscal Estigarribia keeps its character as a border, military and transit town, a gateway to the deep Chaco and the country's great protected areas, like Defensores del Chaco National Park and the Médanos del Chaco. Its history —of war, colonization and life in extreme conditions— continues to set the pulse of one of the most remote and singular corners of Paraguay.