Is grossmont union high school district public or private? Grossmont Union High School District. The Grossmont Union High School District ( GUHSD) is a public school district located in eastern San Diego County, California, and serves high school, adult school, and Regional Occupational Program (ROP) students in the cities of El Cajon, Lemon Grove, and Santee;Who manages the day to day operations of grossmont high school district? The day-to-day operations are managed by the superintendent, who is appointed by the board. The Grossmont Union High School District utilizes a strategic plan that includes a mission statement, district guidelines, core values, and annual goals and objectives.How many high schools are in the san diego union high school district? Formed in June 1920, the union high school district is overseen by a five-member governing board and operates 13 high schools (nine regular, three charter, and one continuation ); a regional occupational program (ROP); and special education and adult education services.