Very Good
#2611 of 9,533 schools in CA
Top 27% in state
Los Osos High
High School · Chaffey Joint Union High
6001 Milliken Ave., Rancho Cucamonga, CA 91737
Enrollment
2,759
Student-Teacher
25.1:1
Score
7.3
Grades
9th – 12th
Enrollment
2,759
Student-Teacher
25.1:1
Score
7.3
Grades
9th – 12th
Updated
2022-23
Updated 2022-23
How this school compares
In Rancho Cucamonga
#1 of 14
public schools
California high schools
#475 of 1,892
In district
#3 of 10
Chaffey Joint Union High
Equity
9.1 / 10
Exceptional
About Los Osos High
Los Osos High serves 2,759 students in grades 9-12 in Rancho Cucamonga, California. This large suburban high school maintains a student-teacher ratio of 25.1:1 with 110 full-time equivalent teachers on staff. The school demonstrates strong academic performance, earning a 7.6 out of 10 MySchoolScout rating and ranking in the 82nd percentile statewide at #1,736 among California's 9,566 schools.
Students excel particularly in English Language Arts, with 82% achieving proficiency or above across grade levels. Mathematics shows room for growth, with 49% of students meeting proficiency standards. Los Osos High draws from an affluent community where the median household income reaches $112,857 and home values average $775,700.
The surrounding neighborhood reflects strong educational values, with 40% of residents holding bachelor's degrees or higher. The area maintains economic stability with a low 8.4% poverty rate among its 23,108 residents. Located on Milliken Avenue in San Bernardino County, Los Osos High operates within Rancho Cucamonga's thriving suburban landscape, serving families who value educational achievement in a well-established community setting.
What Parents Should Know
Los Osos High is a large school with 2,759 students enrolled. Larger schools typically offer a wider range of academic programs, electives, and extracurricular activities. Parents may want to ask about how the school maintains a sense of community and ensures students don't get lost in the crowd.
The student-teacher ratio at Los Osos High is 25.1:1, which is higher than the national average. This may mean larger class sizes, so parents should ask about classroom support, teaching assistants, and how the school differentiates instruction for students who need extra help.
Score Breakdown
Full Profile · 4/4 metricsView breakdown
View breakdown
View breakdown
View breakdown
Los Osos High — Students at Los Osos High score 65% proficient, which is above what's typical for similar communities (expected: 56%).
Equity & Diversity
Shown separately, not included in overall scoreFree/Reduced Lunch
34.4%
Students qualifying for federal meal assistance
Test Scores CA CAASPP (2023-24)
Based on 8 test records from CA state assessments. About our data
Proficiency Trend
→ StableAverage proficiency (% at or above grade level) across Math & ELA over time.
* COVID-affected year — test participation was uneven nationwide. This data is weighted at 50% in the Growth score calculation.
Source: EdFacts (NCES) and state assessment data. Growth score: 6.3/10.
How Los Osos High Compares
See how Los Osos High performs across key quality dimensions compared to state benchmarks.
Funding & Resources
Performance Trends
Math proficiency has declined from 58% (2019) to 48.61% (2024). Reading/ELA proficiency has remained stable from 81% (2019) to 81.78% (2024).
Location
6001 Milliken Ave., Rancho Cucamonga, CA 91737
Nearby Alternatives
Families considering Los Osos High may also want to explore other high schools in the area. John L. Golden Elementary (rated 8.0/10, 1.3 miles away, in nearby Etiwanda), which scores slightly higher. Another option is Victoria Groves Elementary (rated 7.8/10, 1.2 miles away, in nearby Alta Loma), which scores slightly higher. Additionally, Day Creek Intermediate (rated 7.6/10, 1.3 miles away, in nearby Etiwanda), with a very similar rating. For more schools in Rancho Cucamonga, see our Rancho Cucamonga schools guide .
Nearby Schools
20 within 2.2 mi| School | Distance | Rating |
|---|---|---|
| Caryn Elementary Alta Loma | 0.4 mi | 6.1 |
| Banyan Elementary Alta Loma | 0.6 mi | 4.8 |
| Rancho Cucamonga High Rancho Cucamonga | 1.1 mi | 6.2 |
| Carleton P. Lightfoot Elementary Alta Loma | 1.2 mi | 6.9 |
| Victoria Groves Elementary Alta Loma | 1.2 mi | 7.8 |
| John L. Golden Elementary Etiwanda | 1.3 mi | 8.0 |
| Day Creek Intermediate Etiwanda | 1.3 mi | 7.6 |
| Vineyard Junior High Alta Loma | 1.6 mi | 6.6 |
| Windrows Elementary Etiwanda | 1.7 mi | 5.6 |
| Terra Vista Elementary Rancho Cucamonga | 1.9 mi | 5.2 |
| Hermosa Elementary Alta Loma | 1.6 mi | 6.0 |
| MONTESSORI ACADEMY OF ED INC- DBA MONTESSORI ACAD Rancho Cucamonga | 1.8 mi | — |
| Deer Canyon Elementary Alta Loma | 1.8 mi | 6.6 |
| ST MARY'S MONTESSORI SCHOOL Rancho Cucamonga | 1.9 mi | 7.5 |
| Ruth Musser Middle Rancho Cucamonga | 2.2 mi | 5.4 |
| HIGHLAND AVENUE CHRISTIAN SCHOOL Rancho Cucamonga | 1.9 mi | 4.8 |
| Coyote Canyon Elementary Rancho Cucamonga | 2.4 mi | 5.2 |
| Dona Merced Elementary Rancho Cucamonga | 2.4 mi | 4.9 |
| Etiwanda Intermediate Etiwanda | 2.2 mi | 6.2 |
| Etiwanda Colony Elementary Etiwanda | 2.2 mi | 7.4 |
Neighborhood Census ACS (2019-2023)
Census data for ZIP 91737 (ACS 2019-2023 5-Year Estimates) · Data sources
Median Income
$116,903
Median Home Value
$843,500
Median Rent
$2,263/mo
Population
22,797
College Educated
41%
Homeownership
70.2%
Avg Commute
32 min
Poverty Rate
10.1%
Median Age
44.3
Community Profile
The community surrounding Los Osos High has a median household income of $116,903. It is a well-educated community where 41% of adults hold a bachelor's degree or higher. The median home value in the area is $843,500, with a median rent of $2,263/month. The area has a poverty rate of 10.1%. The average commute for residents is 32 minutes. Source: U.S. Census ACS 2022 5-Year Estimates.
Similar Schools
Schools in the same state with comparable level, size, and ratings
| School | Rating |
|---|---|
| Chula Vista Senior High Chula Vista, CA | 7.3 |
| Diamond Bar High Diamond Bar, CA | 7.3 |
| Hesperia High Hesperia, CA | 7.3 |
| Marshall Fundamental Pasadena, CA | 7.3 |
| Monte Vista High Danville, CA | 7.3 |
| Rancho Verde High Moreno Valley, CA | 7.3 |
Frequently Asked Questions
Common questions about Los Osos High
What grades does Los Osos High serve?
Los Osos High serves students in grades 9th through 12th.
How many students attend Los Osos High?
Los Osos High has an enrollment of approximately 2,759 students.
What is the student-teacher ratio at Los Osos High?
The student-teacher ratio at Los Osos High is 25.1:1. A lower ratio generally means more individual attention per student. The national average is approximately 16:1 for public schools.
How does Los Osos High rank in CA?
Los Osos High is ranked #2611 out of 9,533 schools in CA.
What is Los Osos High's MySchoolScout rating?
Los Osos High has a composite rating of 7.3 out of 10 on MySchoolScout. This score combines academic performance, student growth, and school environment into a single score. Equity data is shown separately for context.
What are the test scores at Los Osos High?
Based on the most recent state assessment data, Los Osos High has 54.8% math proficiency and 80.4% reading/ELA proficiency.
Is Los Osos High a charter school?
No, Los Osos High is not a charter school. It is a traditional public school operated by the local school district.
Is Los Osos High a Title I school?
No, Los Osos High is not currently a Title I school.
What does the Free & Reduced Lunch percentage mean for Los Osos High?
34.4% of students at Los Osos High qualify for free or reduced-price lunch. This is a commonly used indicator of economic need and provides important context when interpreting test scores.
Neighborhood Context
- Walk Score
- 16 Car-Dependent
- Transit Score
- 29 Some Transit
- Bike Score
- 32 Somewhat Bikeable
- City Safety
- High (2,116/100K)
Powered by 
FBI UCR 2024. City-level (Rancho Cucamonga). Data >1 year old.
Quick Facts NCES CCD (SY 2022-23)
- Grades
- 9th – 12th
- Enrollment
- 2,759
- Student-Teacher Ratio
- 25.1:1
- Teachers (FTE)
- 110
- Free/Reduced Lunch
- 34.4%
- Type
- regular
- Setting
- Large Suburb
- County
- San Bernardino County
- Phone
- (909) 477-6900
- Data Year
- 2023–2024
Resources & Links
District
Chaffey Joint Union High- District Enrollment
- 22,628
- Schools in District
- 11
- Per-Pupil Spending
- $16,769
- District Rank
- #3 of 10
Other Schools in This District
How We Rate Schools
Every school receives a composite score from 1 to 10 based on four pillars: Academic Performance (50%), Student Growth (20%), Equity (15%), and Learning Environment (15%). Scores are built from publicly available data including standardized test results, enrollment figures, and school climate indicators.
Read our full methodologyRelated reading
- Best Elementary Schools in America: 2026 Rankingsbest schools
- Best Public Schools in California 2026: Top-Ranked Elementary, Middle & High Schoolsbest schools
- Best School Districts to Move To in 2026: A Data-Driven Guidebest schools
- Best Schools in Los Angeles, CA — 2026 Rankingsbest schools
- Best Schools in San Diego, CA — 2026 Rankingsbest schools
Get school insights in your inbox
New rankings, best-schools lists, and parent guides — delivered free. No spam, unsubscribe anytime.
We respect your privacy. Unsubscribe at any time.