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Los Osos High

Public Grades 9-12

209^th

SchoolDigger Rank ?

of 2,162 California High Schools

Better than 90% of California high schools

Summary

Los Osos High is a large, top-performing public high school serving grades 9-12 with nearly 2,800 students in Chaffey Joint Union High School District in Rancho Cucamonga, consistently ranking in the top 10% of all California high schools.

The school is distinguished by its exceptional academic results, with graduation rates above 95% and English Language Arts proficiency far exceeding state and district averages. It stands out as the clear academic leader within its district, outperforming nearby schools like Alta Loma High and Rancho Cucamonga High in key subjects, and is a close competitor with Etiwanda High. Most impressively, Los Osos achieves these outstanding results while effectively supporting an increasing number of students from economically disadvantaged backgrounds, with state rankings in the 93rd-96th percentile for this group and exceptional support for English Language Learners.

Despite a notable increase in student need, the school maintains strong outcomes through efficient use of resources, spending less per student than some lower-performing schools in the area. While mathematics is a relative area for growth compared to its stellar English performance, it still outperforms the district and state. The school has also shown strong resilience and recovery in areas like attendance following pandemic disruptions.

2,759

Students ?

25.7

Student/teacher ratio ?

$23,945

Per pupil spending ?

43.7%

Free/discounted lunch ?

6001 Milliken Ave.
Rancho Cucamonga, CA 91737-7709

(909) 477-6900

District: Chaffey Joint Union High

Feeder schools for Los Osos High:

Elementary:	Banyan Elementary
	Caryn Elementary
	Deer Canyon Elementary
	Floyd M. Stork Elementary
	More...
	Hermosa Elementary
	John L. Golden Elementary
	Victoria Groves Elementary
Middle:	Alta Loma Junior High
	Day Creek Intermediate
	Vineyard Junior High

Racial breakdown:

Hispanic:

41.4%

White:

24.4%

Asian:

22.9%

See top rated California high schools

Compare Los Osos High to nearby high schools!

At a glance

▬ Ranking trend: Holding steady — 89th percentile in 2015 → 90th in 2025

Strengths

✓Test scores above the California average (56% vs 41% meeting standards)

✓Ranks in the top 10% of California high schools

✓96% graduate in 4 years — above the California average (88%)

Worth a look

!Some student groups rank well below the school's overall statewide standing

!Large classes — about 26 students per teacher

Students meeting standards (2024-2025) ?

This school56%

District avg45%

California avg41%

209^th of 2,162

California public high schools ?

Top 10%▲ up 2 pts since 2015

See the entire ranking list of California High Schools →

★★★★★

SchoolDigger rating ?

2^nd of 10High Schools in the Chaffey Joint Union High

393^rd of 1,543Chaffey Joint Union High among California districts

Statewide rank percentile over time (100 = the top-ranked school in the state; click a legend item to add a student group)

Show full rank history (all student groups)

All Students

Year	Avg score	Statewide rank	California percentile	Rating
2025	89.5	209 of 2162	90.3%	★★★★★
2024	93.4	146 of 2159	93.2%	★★★★★
2023	92.9	172 of 2170	92.1%	★★★★★
2022	88.9	215 of 2123	89.9%	★★★★☆
2021	89.4	136 of 1290	89.5%	★★★★☆
2019	87.1	235 of 2133	89.0%	★★★★☆
2018	90.0	200 of 2017	90.1%	★★★★★
2017	85.4	306 of 2021	84.9%	★★★★☆
2016	88.6	221 of 2039	89.2%	★★★★☆
2015	87.3	229 of 1994	88.5%	★★★★☆
2013	83.2	97 of 2426	96.0%	★★★★★
2012	81.8	119 of 2354	94.9%	★★★★★
2011	81.9	115 of 2367	95.1%	★★★★★
2010	82.9	96 of 2281	95.8%	★★★★★
2009	81.5	91 of 2238	95.9%	★★★★★
2008	83.4	84 of 2117	96.0%	★★★★★
2007	87.4	51 of 2063	97.5%	★★★★★
2006	79.4	125 of 1968	93.6%	★★★★★
2005	75.5	156 of 1901	91.8%	★★★★★
2004	68.9	210 of 1653	87.3%	★★★★☆

African American

Year	Avg score	Statewide rank	California percentile	Rating
2025	74.1	100 of 523	80.9%	★★★★☆
2024	83.6	66 of 517	87.2%	★★★★☆
2023	84.1	68 of 521	86.9%	★★★★☆
2022	80.5	73 of 522	86.0%	★★★★☆
2019	64.7	155 of 592	73.8%	★★★★☆
2018	81.1	102 of 582	82.5%	★★★★☆

Asian

Year	Avg score	Statewide rank	California percentile	Rating
2025	78.3	122 of 585	79.1%	★★★★☆
2024	77.6	121 of 573	78.9%	★★★★☆
2023	74.6	156 of 591	73.6%	★★★★☆
2022	76.7	139 of 581	76.1%	★★★★☆
2019	74.7	147 of 582	74.7%	★★★★☆
2018	75.6	155 of 581	73.3%	★★★★☆

Disabled

Year	Avg score	Statewide rank	California percentile	Rating
2022	52.8	360 of 1161	69.0%	★★★☆☆
2021	88.8	44 of 555	92.1%	★★★★★
2019	70.0	207 of 1117	81.5%	★★★★☆
2018	75.0	170 of 1052	83.8%	★★★★☆

English Language Learner

Year	Avg score	Statewide rank	California percentile	Rating
2023	99.3	9 of 1064	99.2%	★★★★★
2022	100.0	2 of 1044	99.8%	★★★★★
2021	95.8	14 of 467	97.0%	★★★★★
2018	99.4	17 of 938	98.2%	★★★★★

Female

Year	Avg score	Statewide rank	California percentile	Rating
2025	86.1	236 of 1906	87.6%	★★★★☆
2024	90.7	166 of 1915	91.3%	★★★★★
2023	90.9	172 of 1915	91.0%	★★★★★
2022	88.7	199 of 1858	89.3%	★★★★☆
2021	89.8	103 of 1054	90.2%	★★★★★
2019	83.1	275 of 1833	85.0%	★★★★☆
2018	88.6	185 of 1760	89.5%	★★★★☆

Hispanic

Year	Avg score	Statewide rank	California percentile	Rating
2025	90.3	125 of 1900	93.4%	★★★★★
2024	94.2	88 of 1902	95.4%	★★★★★
2023	90.8	136 of 1917	92.9%	★★★★★
2022	88.1	149 of 1861	92.0%	★★★★★
2019	82.9	213 of 1814	88.3%	★★★★☆
2018	86.6	199 of 1742	88.6%	★★★★☆

Homeless

Year	Avg score	Statewide rank	California percentile	Rating
2025	95.4	8 of 410	98.0%	★★★★★
2024	80.5	40 of 328	87.8%	★★★★☆
2023	73.9	56 of 299	81.3%	★★★★☆
2022	82.6	29 of 290	90.0%	★★★★★

Low Socio Economic Status

Year	Avg score	Statewide rank	California percentile	Rating
2025	91.0	141 of 2013	93.0%	★★★★★
2024	96.0	72 of 2026	96.4%	★★★★★
2023	93.0	128 of 2030	93.7%	★★★★★
2022	90.0	150 of 1943	92.3%	★★★★★
2021	90.2	85 of 1126	92.5%	★★★★★
2019	83.0	239 of 1937	87.7%	★★★★☆
2018	90.6	155 of 1862	91.7%	★★★★★

Male

Year	Avg score	Statewide rank	California percentile	Rating
2025	86.4	245 of 1942	87.4%	★★★★☆
2024	92.6	149 of 1948	92.4%	★★★★★
2023	91.8	179 of 1963	90.9%	★★★★★
2022	87.0	222 of 1916	88.4%	★★★★☆
2021	86.2	166 of 1122	85.2%	★★★★☆
2019	86.8	215 of 1880	88.6%	★★★★☆
2018	88.9	202 of 1834	89.0%	★★★★☆

Military Connected

Year	Avg score	Statewide rank	California percentile	Rating
2024	79.8	30 of 183	83.6%	★★★★☆
2023	58.7	70 of 190	63.2%	★★★☆☆

Multi-racial

Year	Avg score	Statewide rank	California percentile	Rating
2025	50.2	299 of 577	48.2%	★★☆☆☆
2024	68.9	177 of 574	69.2%	★★★☆☆
2023	66.0	184 of 541	66.0%	★★★☆☆
2022	73.5	123 of 515	76.1%	★★★★☆
2019	33.5	299 of 422	29.1%	★☆☆☆☆
2018	65.6	137 of 366	62.6%	★★★☆☆

Special Education

Year	Avg score	Statewide rank	California percentile	Rating
2025	64.6	310 of 1252	75.2%	★★★★☆
2024	65.1	272 of 1216	77.6%	★★★★☆
2023	59.5	310 of 1197	74.1%	★★★★☆

White

Year	Avg score	Statewide rank	California percentile	Rating
2025	59.7	477 of 1155	58.7%	★★★☆☆
2024	72.5	318 of 1173	72.9%	★★★★☆
2023	78.7	235 of 1193	80.3%	★★★★☆
2022	71.1	311 of 1204	74.2%	★★★★☆
2019	73.6	276 of 1222	77.4%	★★★★☆
2018	81.8	195 of 1173	83.4%	★★★★☆

How student groups rank statewide ? (each group's percentile vs the same group at other schools — higher is better; the +/- beside each compares the group with this school's overall percentile)

English Language Learner (2023)99th percentile+7 vs school

Homeless (2025)98th percentile+8 vs school

Hispanic (2025)93rd percentile+3 vs school

Low Socio Economic Status (2025)93rd percentile+3 vs school

Female (2025)88th percentile-3 vs school

Male (2025)87th percentile-3 vs school

Military Connected (2024)84th percentile-10 vs school

African American (2025)81st percentile-9 vs school

Asian (2025)79th percentile-11 vs school

Special Education (2025)75th percentile-15 vs school

Disabled (2022)69th percentile-21 vs school

White (2025)59th percentile-32 vs school

Multi-racial (2025)48th percentile-42 vs school

By subject vs California (2024-2025) ?

English Language Arts/Literacy79%+30 vs state

Mathematics51%+14 vs state

Science38%+5 vs state

★

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Schools Near Los Osos High

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Ranking:

E Elementary M Middle H High A Alternative P Private

Choose columns to see: Summary School Students/Teachers Ranking Test Scores Finance All

School													Students/Teachers											Ranking (2025)				Ranking (2024)				CAST Science (2025)			Smarter Balanced Assessments English Language Arts/Literacy (2025)		Smarter Balanced Assessments Mathematics (2025)		Per Pupil Expenditures (2025)
Name	Type	Grades	Address	City	Zip	County	District	Is Charter	Is Magnet	Is Virtual	Is Title I	Phone	Enrollment	Full-time Teachers	Student/ Teacher Ratio	Free/Discounted Lunch Recipients	White	Black	Hispanic	Asian	American Indian	Pacific Islander	Two or More Races	Average Standard Score (2025)	Statewide Rank (2025)	State Percentile (2025)	SchoolDigger Rating (2025)	Average Standard Score (2024)	Statewide Rank (2024)	State Percentile (2024)	Rank Change from Previous Year	CAST Science 11th Grade	CAST Science 12th Grade	CAST Science All Grades	Smarter Balanced Assessments English Language Arts/Literacy 11th Grade	Smarter Balanced Assessments English Language Arts/Literacy All Grades	Smarter Balanced Assessments Mathematics 11th Grade	Smarter Balanced Assessments Mathematics All Grades	Per Pupil Expenditures Total	Sub-total from Federal Funds	Sub-total from State/Local Funds
Los Osos High	Public	9-12	6001 Milliken Ave.	Rancho Cucamonga	91737	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 477-6900	2,759	107	25.7	43.7%	674 (24.4%)	164 (5.9%)	1,142 (41.4%)	633 (22.9%)	7 (0.3%)	3 (0.1%)	135 (4.9%)	89.5	209^th of 2162 public high schools	90.3%		93.4	146^th of 2159 public high schools	93.2%	63		37.9	37.9	79.0	79.0	50.9	50.9	$23,945	$23,556	$389
Rancho Cucamonga High	Public	9-12	11801 Lark Dr.	Rancho Cucamonga	91701	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 989-1600	3,221	128	25.1	57.4%	637 (19.8%)	442 (13.7%)	1,385 (43.0%)	513 (15.9%)	9 (0.3%)	20 (0.6%)	209 (6.5%)	86.5	273^rd of 2162 public high schools	87.4%		82.1	372^nd of 2159 public high schools	82.8%	99		39.8	39.8	74.7	74.7	43.2	43.2	$23,960	$23,510	$450
Etiwanda High	Public	9-12	13500 Victoria St.	Etiwanda	91739	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 899-2531	3,446	136	25.3	54.5%	506 (14.7%)	478 (13.9%)	1,787 (51.9%)	461 (13.4%)	12 (0.3%)	10 (0.3%)	187 (5.4%)	89.9	197^th of 2162 public high schools	90.9%		87.4	272^nd of 2159 public high schools	87.4%	75		41.7	41.7	81.0	81.0	46.2	46.2	$23,145	$22,640	$505
Alta Loma High	Public	9-12	8880 Baseline Rd.	Alta Loma	91701	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 989-5511	2,386	96	24.8	60.3%	551 (23.1%)	136 (5.7%)	1,437 (60.2%)	130 (5.4%)	11 (0.5%)	7 (0.3%)	111 (4.7%)	74.1	508^th of 2162 public high schools	76.5%		86	309^th of 2159 public high schools	85.7%	199		27.3	27.5	72.0	72.0	33.3	33.3	$26,587	$26,080	$507
Chaffey Community Day	Public	9-12	1802 East Seventh St.	Ontario	91764	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 985-0966	20	2	9.0	85.0%	0 (0.0%)	4 (20.0%)	16 (80.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)								(n/a)
Chaffey District Online High	Public, Virtual	9-12	1802 East 7th St.	Ontario	91764	San Bernardino County	Chaffey Joint Union High	No	(n/a)	Yes	(n/a)	(909) 985-0966	93	5	18.3	62.4%	22 (23.7%)	4 (4.3%)	55 (59.1%)	6 (6.5%)	0 (0.0%)	0 (0.0%)	6 (6.5%)	86	286^th of 2162 public high schools	86.8%		97.1	67^th of 2159 public high schools	96.9%	219		50.0	50.0	58.3	58.3	65.2	65.2	$30,020	$29,930	$90
Summit High	Public	9-12	15551 Summit Ave.	Fontana	92336	San Bernardino County	Fontana Unified	No	(n/a)	No	(n/a)	(909) 357-5950	2,725	111	24.5	72.1%	204 (7.5%)	273 (10.0%)	1,956 (71.8%)	206 (7.6%)	3 (0.1%)	19 (0.7%)	62 (2.3%)	71.7	565^th of 2162 public high schools	73.9%		63.8	679^th of 2159 public high schools	68.6%	114	30.8	28.1	30.7	76.1	76.1	34.6	34.6	$72,392	$63,392	$9,000
Valley View High (Continuation)	Public	9-12	1801 East Sixth St.	Ontario	91764	San Bernardino County	Chaffey Joint Union High	No	(n/a)	No	(n/a)	(909) 985-0966	370	25	14.8	84.9%	33 (8.9%)	28 (7.6%)	289 (78.1%)	7 (1.9%)	3 (0.8%)	1 (0.3%)	8 (2.2%)	13.5	1856^th of 2162 public high schools	14.2%		13.6	1867^th of 2159 public high schools	13.5%	11		6.1	6.1	11.1	11.1	3.4	3.4	$46,265	$45,128	$1,137
Fontana A. B. Miller High	Public	9-12	6821 Oleander Ave.	Fontana	92336	San Bernardino County	Fontana Unified	No	(n/a)	No	(n/a)	(909) 357-5800	1,950	97	20.1	75.3%	68 (3.5%)	84 (4.3%)	1,722 (88.3%)	47 (2.4%)	5 (0.3%)	5 (0.3%)	18 (0.9%)	59.7	830^th of 2162 public high schools	61.6%		53.6	916^th of 2159 public high schools	57.6%	86	26.6	0.0	25.9	61.5	61.5	29.4	29.4	$53,931	$46,852	$7,079
Upland High	Public	9-12	565 West 11th St.	Upland	91786	San Bernardino County	Upland Unified	No	(n/a)	No	(n/a)	(909) 949-7880	2,797	125	22.3	69.5%	478 (17.1%)	205 (7.3%)	1,812 (64.8%)	205 (7.3%)	0 (0.0%)	8 (0.3%)	79 (2.8%)	76.1	476^th of 2162 public high schools	78.0%		73.7	511^th of 2159 public high schools	76.3%	35	42.5	14.8	41.3	66.1	66.1	36.6	36.6	$21,338	$16,348	$4,990

Frequently Asked Questions about Los Osos High

How many students attend Los Osos High?

In the 2024-25 school year, 2,759 students attended Los Osos High.

Is Los Osos High a good school?

Yes. Los Osos High ranks in the top 9.7% of California high schools.

What is the racial makeup of Los Osos High?

Students at Los Osos High are 41% Hispanic, 24% White, 23% Asian, 6% African American, 5% Two or more races.

What schools feed into Los Osos High?

Los Osos High is fed by the following schools:

Elementary : Banyan Elementary
Elementary : Caryn Elementary
Elementary : Deer Canyon Elementary
Elementary : Floyd M. Stork Elementary
Elementary : Hermosa Elementary
Elementary : John L. Golden Elementary
Elementary : Victoria Groves Elementary
Middle : Alta Loma Junior High
Middle : Day Creek Intermediate
Middle : Vineyard Junior High

What district is Los Osos High in?

Chaffey Joint Union High

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Latest California data All new data »

2024–25 school spending dataJul 1, 2026

2024–25 attendance dataMar 13, 2026

2024–25 CSA Spanish test scoresDec 22, 2025

2024–25 dropout rates & graduation ratesNov 14, 2025

SchoolDigger data sources: National Center for Education Statistics, U.S. Department of Education, the U.S. Census Bureau and the California Department of Education.

IMPORTANT DISCLAIMERS: Not all boundaries are included. We make every effort to ensure that boundaries are up-to-date. But it's important to note that these are approximations and are for general informational purposes only. To verify legal descriptions of boundaries or school locations, contact your local tax assessor's office and/or school district.