The William S. Hart Union High School District, located in the northern part of Los Angeles County, serves approximately 21,000 students in grades seven through twelve in the Santa Clarita Valley. The Hart District combines a rich tradition of history with a strong sense of community – ONE HART. Across the District’s seven comprehensive high schools, a continuation school, early college high school, independent study school, six junior high schools, an adult school, and a unique program serving students with significant emotional issues you will find 2,000 staff members committed to preparing our students for the many opportunities they will encounter in their future.