Concepción de Ataco is a municipality and city within the Ahuachapán Department, El Salvador. It has an area of 61.03 km ² and a population of 18,101 inhabitants (est. 2006).The municipality administration is divided into 11 cantons, which are: El Arco, El Limo, El Naranjito, El Tronconal, La Ceiba, La Joya de los Apante, La Planxa, San Jose, Shucutitán and Texusín Chirizo. Ataos's population has pre-Columbian origin and was founded by Yaqui Indians or pipiles in central Apaneca Mountain Range.In Nahuatl, Ataco means "high place of springs.”Concepción de Ataco's "sister city" is Elk Grove, California.HistoryArchbishop Pedro Cortes y Larraz, Ataco in 1770 belonged to the parish and its people Ahuachapán was represented by 303 families with 784 indigenous people who spoke the Nahuatl of the Pipil turn these people spoke and understood also Castilian.In the colonial period Ataco belonged to the administration of the province or municipality over Izalco Sonsonate. As of June 12, 1824 belonged to the municipality of primitive and great department of Sonsonate. Because the law of July 4, 1832 this population was made part of the jurisdiction of the judicial district of Ahuachapán. By legislative decree of February 8, 1855 the town was incorporated in the department of Santa Ana. According to a municipal report dated 20 April 1858, Ataco had a population of 972 inhabitants.During the year 1866 the municipalities of Ataco asked the authorities, that this population be divided and separated from the department of Santa Ana and Sonsonate department add for convenience of local interests. This application did not succeed.By Legislative Decree dated 26 February 1869 Ataco joined the district and department of Ahuachapán.In the year 1890 the city had 2.860 inhabitants.