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About Us

The Chaffey Joint Union High School District serves the communities of Ontario, Montclair, Rancho Cucamonga, and portions of Fontana, Upland, Chino, and Mount Baldy. With over 25,000 students, the District is the fourth largest high school district in California. It has eight comprehensive high schools, a continuation high school, an online high school, a community day school, an adult school, and alternative programs. The District offers a wide variety of instructional options that provide a quality education for each student, every day. The District's well-prepared, dedicated, and highly qualified teachers and support personnel are second to none.
 
The Chaffey Joint Union High School District Board of Trustees are steadfast in the belief that "Nothing is more important than student learning and their achievement."
 
Our daily purpose encompasses our commitment:
"To provide student learning, and ultimately their achievement, of the prescribed curriculum that takes place in the classroom under the direction of the teacher." The Chaffey District supports this daily act. We realize that our efforts uniquely influence the future of our community and of this nation, and we are passionate about doing whatever it takes to prepare students to be successful and contributing citizens of the 21st century.
 
The Chaffey District has provided a quality education for high school students in the area since 1911. As the District continues to grow and progress, we are poised to meet the challenge of providing the finest quality education possible for every student. 
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All CJUHSD students will graduate ready for college and careers.

Recent News

WeTip - Be the solution

WeTip

Be the Solution. If you have information regarding crime or misconduct at your school, call WeTip anonymously.

The Chaffey District Cares

The Chaffey District cares about your mental well-being. We partner with community agencies and mental health professionals to provide support to our students and staff. If you, or someone you know, is in crisis please contact the Community Crisis Response Team (909) 421-9233 - Click 'Read Full Story' for more information.
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Upcoming Events

Board Meeting

Time: 5 PM
Location: Montclair High School
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School Facts

  • 78% of Los Osos High School graduates meet the University of California and California State University A-G admissions requirements, making it a leader in San Bernardino County.
  • 98% of freshmen at Los Osos High School complete their first year of high school on track to graduate.
  • The CJUHSD has been named a Top Workplace by the Press-Enterprise and Inland News Group.
  • 2500 Advanced Placement exams are administered to students at Los Osos High School annually.

Principal's Message

Eric Cypher
Grizzlies Staff, Parents, Guardians, and Students, 

I hope you had a restful Thanksgiving Break. Thank you for all you do for our school and our community as you all continue to make this place the best place to learn and grow.  

We are in the home stretch of the first semester with finals less than a week away! Students, the winter break is right around the corner, please continue to work hard to finish the semester strong and successfully. Parents, I encourage parents to look over their students' progress report and use that information to assess progress in each class. Also, parents, please continue to monitor Canvas and communicate with teachers and counselors if you have any concerns. 
 
Tutoring is still available! I encourage students to take advantage of before and after school tutoring, available in the library and the two remaining Saturday schools to help support students on 12/7 and the annual Coco and Cram on 12/14.   
 
Parents, please continue to help your student by reviewing their progress and ensuring their homework is complete. Also, please check attendance to make sure your student is attending EVERY class, EVERY day. 
Finals will be held on Tuesday, Wednesday, and Thursday, December 17th-19th. All students should begin preparing for finals by reviewing the content they have learned to prepare for their final exams. Friday, Dec. 20th there will be no school. 
 
Final Schedule:
  
  Tuesday, December 17, 2024             Bell Schedule 

  Period 0..............................................7:20am – 8:23am 
  Period 2..............................................8:30am – 10:30am 
  BRUNCH..........................................10:30am – 10:43am 
  Period 4............................................10:50am – 12:50pm 
  Period 7............................................12:57pm – 2:00pm 
 
  Wednesday, December 18, 2024        Bell Schedule  

  Period 0............................................7:20am – 8:23am 
  Period 3............................................8:30am – 10:30am 
  BRUNCH.........................................10:30am – 10:43am 
  Period 5...........................................10:50am – 12:50pm 
  Period 7...........................................12:57pm – 2:00pm 
 
 Thursday, December 19, 2024             Bell Schedule 

 Period 1..............................................8:30am – 10:30am 
 BRUNCH..........................................10:30am – 10:43am 
 Period 6............................................10:50am – 12:50pm 
 
  
Lastly, I wish you all a safe and happy holiday season. Enjoy the winter break and I look forward to our return on Monday, January 6th. 

Claws UP Grizzlies! 

Eric Cypher 
Principal, Los Osos High School 
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