Very Good
#2073 of 9,539 schools in CA
Top 22% 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
7.7
Grades
9th – 12th
Enrollment
2,759
Student-Teacher
25.1:1
Score
7.7
Grades
9th – 12th
Data vintage
2022-23
Data vintage2022-23
How this school compares
California schools
#2,073 of 9,539
In Rancho Cucamonga
#2 of 14
public schools
In district
#2 of 10
Chaffey Joint Union High
Equity
9.1 / 10
Excellent
Shortlisting around Los Osos High?
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Los Osos High
High School in Rancho Cucamonga · grades 9th – 12th. Start here, then compare fit against nearby and district options.
Caryn Elementary
0.4 mi away. Use as a geographic alternative in the same move search.
Banyan Elementary
0.6 mi away. Use as a geographic alternative in the same move search.
About Los Osos High
Los Osos High is a public high school in Rancho Cucamonga, CA, part of Chaffey Joint Union High. Los Osos High serves approximately 2,759 students, and covers grades 9th-12th, and has a 25.1:1 student-teacher ratio. Los Osos High has a current MySchoolScout rating of 7.7 out of 10 and ranks #2,073 of 9,539 schools in CA.
Structured state assessment records for Los Osos High show 62% math proficiency (multi-year average, 2009-2024) and 77% reading/ELA proficiency (multi-year average, 2009-2024).
- This school 7.7 · Very Good
- District avg 7.1
- CA avg 6.5
What Parents Should Know
Los Osos High is a large school: 2,759 students. Size usually brings more course choices and activities than a smaller school can staff, but kids can also blend into the crowd. Ask how the school keeps students known and supported.
Los Osos High runs 25.1:1 students to teachers, above the national average. That often means bigger classes. Ask how the school supports kids who need extra help, and whether there are teaching assistants or small-group time.
Score Breakdown
Full Profile · 4/4 metricsView breakdown
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Los Osos High — Students at Los Osos High score 65% proficient, which is above what's typical for similar communities (expected: 55%).
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 30 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: 8.3/10.
How Los Osos High Compares
See how Los Osos High performs across key quality dimensions compared to state benchmarks.
Funding & Resources
Programs & Offerings
Data as of 2021-22 · Source: CRDC via Urban Institute · Learn more
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 8.6/10, 1.3 miles away, in nearby Etiwanda), which scores slightly higher. Another option is Carleton P. Lightfoot Elementary (rated 8.5/10, 1.2 miles away, in nearby Alta Loma), which scores slightly higher. Additionally, Day Creek Intermediate (rated 8.5/10, 1.3 miles away, in nearby Etiwanda), which scores slightly higher. 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 | 7.9 |
| Banyan Elementary Alta Loma | 0.6 mi | 7.9 |
| Rancho Cucamonga High Rancho Cucamonga | 1.1 mi | 7.3 |
| Carleton P. Lightfoot Elementary Alta Loma | 1.2 mi | 8.5 |
| Victoria Groves Elementary Alta Loma | 1.2 mi | 7.7 |
| John L. Golden Elementary Etiwanda | 1.3 mi | 8.6 |
| Day Creek Intermediate Etiwanda | 1.3 mi | 8.5 |
| Vineyard Junior High Alta Loma | 1.6 mi | 7.4 |
| Windrows Elementary Etiwanda | 1.7 mi | 6.7 |
| Terra Vista Elementary Rancho Cucamonga | 1.9 mi | 8.1 |
| Hermosa Elementary Alta Loma | 1.6 mi | 5.6 |
| MONTESSORI ACADEMY OF ED INC- DBA MONTESSORI ACAD Rancho Cucamonga | 1.8 mi | — |
| Deer Canyon Elementary Alta Loma | 1.8 mi | 6.8 |
| ST MARY'S MONTESSORI SCHOOL Rancho Cucamonga | 1.9 mi | 7.5 |
| Ruth Musser Middle Rancho Cucamonga | 2.2 mi | 6.2 |
| HIGHLAND AVENUE CHRISTIAN SCHOOL Rancho Cucamonga | 1.9 mi | 4.8 |
| Coyote Canyon Elementary Rancho Cucamonga | 2.4 mi | 7.1 |
| Dona Merced Elementary Rancho Cucamonga | 2.4 mi | 6.0 |
| Etiwanda Intermediate Etiwanda | 2.2 mi | 7.0 |
| Etiwanda Colony Elementary Etiwanda | 2.2 mi | 7.3 |
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
Similar Schools
Schools in the same state with comparable level, size, and ratings
| School | Rating |
|---|---|
| Colton High Colton, CA | 7.7 |
| Corona del Mar High Costa Mesa, CA | 7.7 |
| Cosumnes Oaks High Elk Grove, CA | 7.7 |
| Crescenta Valley High La Crescenta, CA | 7.7 |
| Dos Pueblos Senior High Goleta, CA | 7.7 |
| Eastlake High Chula Vista, CA | 7.7 |
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 ranks #2,073 of 9,539 schools in CA.
What is Los Osos High's MySchoolScout rating?
Los Osos High has a current MySchoolScout rating of 7.7 out of 10. This score combines the level-appropriate components shown in the rating breakdown; equity data is shown separately for context.
What are the test scores at Los Osos High?
Based on loaded state assessment records, Los Osos High has 62% math proficiency (multi-year average, 2009-2024) and 77% reading/ELA proficiency (multi-year average, 2009-2024).
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
Powered by 
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
- Chronic Absenteeism (SY 2022-23)
- 19.2%
- Phone
- (909) 477-6900
- 4-Year Graduation
- 95.0%
Resources & Links
District
Chaffey Joint Union High- District Enrollment
- 22,628
- Schools in District
- 11
- Per-Pupil Spending
- $16,769
- District Rank
- #2 of 10
Other Schools in This District
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