Rancho San Diego, California landscape and open-space maintenance. Rancho San Diego is served by the Cajon Valley Union School District and the Grossmont Union High School District. Steele Canyon High School and Valhalla High School are the primary schools in this location. Rancho San Diego is also home to the Cuyamaca College Coyotes. Rancho San Diego, California Rancho San Diego is a census-designated place (CDP) in San Diego County, California. The population was 21,208 at the 2010 census, up from 20,155 at the 2000 census. The area was developed as subdivisions beginning in the 1970s. Rancho San Diego is located at (32.765985, -116.921477). According
San Diego County, California cable companies. San Diego County has 18 federally recognized Indian reservations, more than any other county in the United States. Although they are typical in size to other Indian reservations in California (many of which are termed "Rancherías"), they are relatively tiny by national standards, and all together total of area. The population ranking of the following table is based on the 2010 census of San Diego County. † "county seat" San Diego County, California San Diego County () is a county in the southwestern corner of the state of California, in the United States. As of the 2010 census,