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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

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Upcoming Events

Board Meeting

Time: 12 PM
Location: Los Osos High School

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
Grizzly Nation,  
 
We are excitedly approaching the end of the school year, with our final day set for Thursday, May 22, 2025! Let’s keep our momentum going and finish the year strong as we look forward to some much-needed rest and celebration. 
 
This date also marks one of the most important milestones of the year—Graduation Day! We can’t wait to celebrate the Class of 2025 and all they’ve accomplished. Seniors should arrive on campus by 5:00 PM, with stadium doors opening at 5:15 PM. The ceremony will begin promptly at 6:30 PM at our Grizzly Football Stadium. 
 
To ensure a respectful and memorable event for all, balloons and noisemakers will not be permitted inside the stadium. This is a truly momentous occasion, and we appreciate your understanding and cooperation in maintaining the dignity of the ceremony as we honor our graduates. 
 
Additionally, final exams are right around the corner. Finals for all students will be held May 20th–22nd. Please note that seniors will take their 1st and 2nd period finals on May 16th and19th, and complete the rest of their exams on May 20th and 21st. 
 
Let’s make these last few days count—push through, support each other, and celebrate all the hard work that’s brought us to this exciting point in the year! 
  
Finals Week Schedule  
Friday and Monday, May 16th and 19th – Senior Final Exams during periods 1 and 6 ONLY (regular bell schedule) 
 
Tuesday, May 20, 2025 (finals, grades 9-12)     

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, May 21, 2025 (finals, grades 9-12)     

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, May 22, 2025 (finals, grades 9-11)

Bell Schedule 

Period 1                                                                  8:30am – 10:30am 
BRUNCH                                                              10:30am – 10:43am 
Period 6                                                                 10:50am – 12:50pm 

*Students in a 0 or 7th period, see your 0 or 7th period teacher for finals information.  
  
As we close out an incredible school year, I want to extend a heartfelt thank you for your unwavering support of our school—and, most importantly, for supporting your student every step of the way. This year, our students have shown remarkable resilience, rising to meet challenges with determination and grace. They’ve worked hard, stayed committed, and truly embodied what it means to be W.I.L.D.—Working Hard, Inspiring Others, Leading with Integrity, and Dreaming Big. 
 
Looking ahead, we’re excited to offer a robust summer school program beginning May 28, 2025. This is a great opportunity for students to continue their learning journey, get ahead, or make up credits. If your student is interested, please contact their counselor as soon as possible to discuss available options. 
 
To the Class of 2025—congratulations! We are incredibly proud of everything you’ve accomplished, and we look forward to celebrating your success as you take your next big steps. 
 
It continues to be my greatest honor and privilege to serve as your principal. Let’s stay focused and finish the year strong, proud, and W.I.L.D.—and then enjoy a well-deserved summer break! 
  
Eric Cypher