Our Lady of the Holy Rosary School was opened on September 29, 1950 in order to serve the families of the community of Roscoe, now known as Sun Valley. Students in grades one through four met in the parish hall and in a nearby utility house until the following year, when the first unit of the school was finished. That same year, the parish began constructing a second six-room unit. In 1956, the third unit was completed making Our Lady of the Holy Rosary a double-grade school. A kindergarten was opened in 1981 and in 2010, a Pre-School/Pre-Kinder program was added.
From 1950 until 1971, Our Lady of the Holy Rosary was staffed by the Sisters of Charity of Providence. From 1971 to 1983, the school was directed by a lay principal. In 1983, the Sister Servants of the Blessed Sacrament took over the administration of the school and continues to this day. Our school is an elementary, Pre-School through 8th grade Parish School and is accredited by the WASC/WCEA.