Los Osos High School Home

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. 
About Us Image
All CJUHSD students will graduate ready for college and careers.

Recent News

Colorectal Cancer: know the Signs and Symptoms

Community Education

Colorectal Cancer: Know the Signs and Symptoms. Join us on Wednesday, September 29, 2021 at 6:30 PM for this information virtual event.
Canvas Logo


CJUHSD has adopted Canvas as our new Learning Management System

Upcoming Events

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
Dear Los Osos High School Students, Parents, Guardians, and Caregivers,
Welcome to the 2021-2022 school year! The first days of school are always filled with excitement and anticipation and this school year will be like no other as we continue to emerge from Covid restrictions.  
We look forward to fully welcoming students back to in-person instruction this fall, with the first day of the 2021-2022 school year on Monday, August 9th.  Beginning this school year for 2021-22, the hours for all schools in the Chaffey Joint Union High School District will shift to 8:30 a.m. - 3:20 p.m. Friday hours will be from 9:30 a.m. - 3:20 p.m. This shift to a later start time is to prepare for the legally-mandated late start for California high schools in 2022. Our bell schedule is attached and features a traditional 6-period day, with expanded 0 and 7-period opportunities for students who need additional access to academic courses.  
The District remains committed to ensuring the safety of our students and staff. We will continue to monitor and adapt to health regulations from the state as well as the county. Additionally, the district has established a current safety plan approved by the county of public health that outlines the safety procedures and protocols to protect students and staff. As part of this plan, we will continue to frequently clean and disinfect restrooms, classrooms, and common areas using approved products that meet the County Department of Public Health Standards, thus ensuring a clean and safe environment.
We encourage all students to return to in-person instruction but will provide alternatives for those students who may need to remain in a virtual learning setting. We will work individually with families to determine the best setting for their student. If you desire to discuss an alternative educational program for your student, please contact the school at 909-477-6900 this summer, and together we will explore the best options for your student.
Moving forward into next school year we are excited to celebrate two decades of excellence for the Grizzlies! Los Osos was founded in 2002, and in that time, we are proud to recognize Los Osos as both a California Distinguished School and a California Gold Ribbon School. 20 years of excellence is much to celebrate but we also recognize that there is still much work to do. Our staff has been working tirelessly looking for ways to improve academic instruction and achievement, provide for socio-emotional learning development, and exploring instructional strategies for mitigating learning loss due to Covid.  Additionally, we will continue to evaluate and improve upon our systems and practices to provide for equitable instruction and access for all students. We will continue to work on building positive relationships with our students and families while working with the community to ensure our students are College and Career Ready. 
Parents, your role in your student’s development is paramount to their success. Please continue emphasize the importance of student learning, continue to discuss the importance of communication with teachers, and continue to monitor your students grades and academic progress through Canvas. These three items are essential for fulfilling our vision of all students graduating ready for college and careers. Parents your involvement helps to build a healthy partnership with the school and if you would like to do more, please consider joining our PTSA! Our PTSA works to support our entire student body and in the past three years they have raised money to beautify our campus, provide for student scholarships, and provided academic resources and support for our staff and students. Their daily efforts are an essential part of the Grizzly Success.  
2021-2022 is an exciting year ahead and we look forward to celebrating with you two decades, at place where excellence is a habit! Should you have any questions please do not hesitate to give us a call at (909) 477-6900.
To maintain the safety of students, their families, and our LOHS staff, the registration procedures for the upcoming 21-22 school year have changed. Students, parents and staff will be required to wear face coverings and maintain social distancing while attending our summer registration days.
Students: please remember to bring any textbooks you have so you can return them to the library on your designated registration day and time as indicated below:
Students/families will report for schedule pick-up/orientation based on last name according to the schedule below:
Tuesday, July 27 Seniors  
  Last Names A - Mas 8am - 9:30am
  Last Names Mat - Z 9:30am - 11am
Wednesday, July 28 Juniors  
  Last Names A - Mas 8am - 9:30am
  Last Names Mat - Z 9:30am - 11am
Wednesday, July 28 Sophomores  
  Last Names A - Mas 12pm - 1:30pm
  Last Names Mat - Z 1:30pm - 3pm
Thursday, July 29 Freshmen  
  Last Names A - Mas 8am - 10am
  Last Names Mat - Z 12pm - 2pm
Friday, July 30 Make-up Day (Admin Office) 8am - 11am
Claws Up!
Eric Cypher
Principal of Los Osos High School