Diamond Ranch High School (or DRHS) is a high school (secondary school) that serves students from Diamond Bar and Phillips Ranch, CA and is operated by the Pomona Unified School District (PUSD) in Pomona, California. In 2003, Diamond Ranch was named as a California Distinguished School by the California Department of Education. In April 2007, it was named a California Distinguished School for the second time. The school has won many awards from a spot in America's Best High Schools to being named a California Distinguished School.