José de Berroterán was commander of the presidios of Mapimí and Conchos in Mexico for thirty-five years. While captain of Presidio de Conchos he was ordered to command an expedition to explore the territory from San Juan Bautista up the Rio Grande to the mouth of the Río Conchos. This area was part of what was known as the Despoblado, a refuge for groups that preyed on the frontier settlements of Nueva Vizcaya and Coahuila. Berroterán left Conchos on January 13, 1729, with fifty-eight soldiers, six Indian guides, and more than 500 horses and mules, and arrived at San Juan Bautista on March 15. There, joined by another fifteen soldiers and forty Indians, he began his exploration on March 29. The group traveled west of the Rio Grande to the Río San Antonio, twenty-five miles west of the site of present Eagle Pass, where Berroterán received orders to divide his troops into three parts; two groups were to fend off attacks of roving tribes at Presidio de Coahuila (Monclova) and Santa Rosa de Nadadores, and one was to proceed to Cuatro Ciénagas. After holding a meeting with his officers, Berroterán decided not to follow the orders because the tribes would be gone before his troops could reach the places attacked and the third group would not be large enough to continue the mission. The expedition continued along the west bank of the Rio Grande and reached the site of present Ciudad Acuña on April 12. Unable to continue along the river because of the canyon, the group made a long detour to the west and finally crossed the Rio Grande near the site of present Langtry on April 19. On April 28 in another meeting with his officers, Berroterán decided that it was too difficult to continue the march with the limited supplies on hand. He ordered the detachment from Coahuila to return to its presidio by way of Santa Rosa de Nadadores; the remaining groups left the following day, and arrived at Nueva Vizcaya on May 16. In his report, submitted to the viceroy, Berroterán states, "The gulf or pocket [the Despoblado]...contains steep places, dry places, few waterholes, and great distances. ...For this reason it cannot be inhabited nor populated by rational Christians." He was severely criticized by Brigadier Pedro de Rivera y Villalón, who said the mission was a failure because Berroterán made too much of the hardships and depended too much on his Indian guides. The auditor, Juan Manuel de Oliván Rebolledo, agreed, although he allowed that one purpose–to open communications between Nueva Vizcaya and Coahuila–had been accomplished. Berroterán was charged with "laxity of duty" in a report to the governor of Parral on June 17, 1730.