Nuestra Señora de la Candelaria, the third of three San Xavier missions, which also included San Ildefonso and San Francisco Xavier de Horcasitas, was founded by the College of Santa Cruz de Querétaro under the leadership of Father Mariano Francisco de los Dolores y Viana. It was on the south bank of the San Gabriel River (then known as the San Xavier River) about five miles from the site of present Rockdale in Milam County. This mission, originally designed to serve the Tonkawa Indians, was founded in July 1749 to congregate Coco Indians and their allies, including the Tops and Karankawas. The Cocos had been waiting at Mission San Ildefonso for the establishment of Mission Candelaria, but they fled in March 1749 because of harassment from soldiers stationed in the area. The missionaries succeeded in recongregating the Cocos at the mission. By the time of Capt. José Joaquín de Ecay Múzquiz's inspection tour to select a presidio site in the summer of 1750, the mission had ninety residents and had recorded fifty baptisms.
Although there was constant squabbling between the San Xavier missions and the military force sent to protect them, Mission Candelaria had a particularly unfortunate association with the soldiers. When San Francisco Xavier de Gigedo Presidio was established near the mission in 1751, Father Miguel de Pinilla of Mission Candelaria became the chaplain for the garrison of fifty men. The commander of the presidio, Capt. Felipe de Rábago y Terán, decided upon his arrival that the missions should be moved, and he constantly undermined their work. He also became involved with the wife of one of his soldiers. In the ensuing scandal, the aggrieved husband, Juan José Ceballos, fled to Mission Candelaria. Rábago y Terán violated the sanctuary of the mission to return Ceballos to the presidio and released him to the mission only after strong protests from Father Pinilla. Relations between the captain and the chaplain continued to deteriorate as reports of lewd behavior among the Spanish troops spread to the mission community. Finally, after consulting with other missionaries, Pinilla excommunicated the garrison. The order was lifted after each soldier requested penance. A new crisis emerged when the garrison severely beat a Coco Indian when he entered the presidio with his weapons. As a result of the beating, the Cocos fled Mission Candelaria. Several days after they left, Father Juan José de Ganzabal and Ceballos were dining with Father Pinilla at the mission when they were attacked by unknown assailants. Ceballos died from a gunshot wound, while Father Ganzabal took an arrow through the heart. Rábago y Terán blamed the murders on the missing Coco Indians, but subsequent events suggested that the captain himself was behind the murders. The entire incident raised questions about moving the missions closer to San Antonio. During the next four years, Mission Candelaria was occupied intermittently by Bidais, Orocoquisas, and Cocos. The San Gabriel River location was finally abandoned without official sanction in 1755 after a severe drought and epidemic. In 1756 all mission property was transferred to the new Santa Cruz de San Sabá Mission, which was established to serve the Lipan Apaches. The Coco Indian neophytes from Mission Candelaria were moved to San Antonio de Valero Mission in San Antonio. A historical marker in Milam County commemorates Candelaria Mission.