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About Our School


Welcome to Grizzly Country!  Los Osos High School, located in the foothills of the San Bernardino Mountains in the suburban community of Rancho Cucamonga, is one of eight comprehensive high schools in the Chaffey Joint Union High School District (CJUHSD).  Chaffey is the fourth largest high school district in the state of California.  Los Osos High School first opened its doors in August of 2002 and students quickly lived up to its motto, “Where Excellence is a Habit”.  We are solidly entrenched as one of the premier high schools in the Inland Empire, becoming a California Distinguished School in 2013 and earning a six year WASC accreditation in that same year. We embrace our reputation as a rigorous, competitive high school focused intensely on the success and well-being of approximately 3200 students, providing them with an excellent education in preparation for college and careers.

Student learning is our top priority and not only do Los Osos students excel in the classroom, but Grizzlies have proven themselves to be high achievers in the arts and athletics as well.  Their outstanding achievements in these fields complement their academic studies and promote their overall growth and development.  Our award winning visual and performing arts programs are second to none and our athletic programs are extremely competitive and have claimed numerous League championships in our young history.  Our school provides a bustling and spirited student activities program including 80 chartered clubs, allowing all students a place to make a connection and immerse themselves in school culture