In pre-Columbian times this area, now in the canton of La Unión, was inhabited by Indians of the North Huetar kingdom, domains of the chief Guarco. At the time of the conquest the principal chief of the region was Guarco's son, Correque. In the eighteenth century some parish priests from the Church of the Holy Spirit of Esparza City, accompanied by natives of Salamanca, were heading to the city of Cartago. On their way they traveled through the valley of the Three Rivers, as it was called at that time. They settled there, thus giving rise to a more stable population. They built a small chapel that was dedicated to the Virgen del Pilar, whose image had been given to them by Bishop Hall. Thus the fledgling town was named for Our Lady of the Pillar of Three Rivers, or simply people of Pilar. The people of Three Rivers are sometimes known as "Pilaricos". In relation to the name of the canton there are two popular versions. One concerns a group of Spanish missionaries from a convent in Guatemala, arriving accompanied by Indians of different cultural groups. The small town they established was called La Unión, to commemorate their friendliness and brotherhood. The other version is attributed to the fact that the location of the town is at the junction of three rivers, now called Tiribi, Shorty and The Cross so that the village then became known as The Union of Three Rivers.
Coffee
Tres Ríos coffee is recognized internationally as one of the best in the world for its high quality. Its unique flavor is due to the high fertility and composition of the region's soils, which have been enriched by minerals in the various eruptions of Irazú Volcano and to an ideal balance of moisture from rains and warm summers. Due to a dynamic urban growth in the metropolitan area of Costa Rica in the late twentieth century, the land use has progressively changed from agricultural to suburban, forcing the elimination of dozens of coffee farms. However, the Tres Rios area still continues to grow coffee beans for the gourmet market. The economy of Tres Rios is now diversified and no longer depends only on the cultivation of coffee. Urban development and geographical location close to other densely populated metropolitan suburbs and midway between the cities of San José and Cartago have oriented its economy to trade and services, including the development of many private schools.
