Enrollment
422
California · 2024-25 NCES data
Elementary school (grades K-5) · Petaluma, CA
Sonoma Mountain Elementary
Federal NCES profile for Sonoma Mountain Elementary, including enrollment, faculty, free-lunch eligibility, demographics, and resource indicators - Resource Investment Index 33/100.
2024-25 NCES dataElementary school (grades K-5)NCES 062832007455Charter school
👥 S:T ratio 0
🌟 Gifted program 70
🎓 Counselors 0
📋 Attendance 61
Scored 0–100 from federal NCES and CRDC indicators, resource allocation, not test scores. Full methodology →
The verdict
Sonoma Mountain Elementary earns 33/100 on the Resource Investment Index, with class sizes larger than 87% of California schools.
- #15 of 25
- elementary schools in Petaluma · Resource Index
- 33
- Resource Index · Typical
- 26.4:1
- large classes for California
- 10.5%
- free-lunch eligible
Sonoma Mountain Elementary has class sizes larger than 87% of California schools. Computed live against every California school reporting to NCES.
By Resource Investment Index, Sonoma Mountain Elementary ranks #15 of 25 elementary schools in Petaluma, CA.
School address
District: Old Adobe Union · California
NCES ID 062832007455 Verify on NCES CCD record →
Teachers (FTE)
16.0
Federal CCD staff survey
Students per teacher
26.4:1
vs 21.5:1 California avg
+23% vs state
Free-lunch eligible
10.5%
vs 55.5% California avg
-81% vs state
Student-teacher ratio in context
How Sonoma Mountain Elementary compares with California and U.S. medians
What stands out at Sonoma Mountain Elementary
Sonoma Mountain Elementary is a lower-poverty, mid-sized charter elementary school in Petaluma, California, enrolling 422 students.
Class loads run heavy: 26.4:1 is larger than about 87% of California schools and 23% above the 21.5:1 state mean, so each teacher carries more students than is typical.
Comparatively few students face economic hardship here, 10.5% free-meal eligibility runs 81% below the California average.
With 422 students, its enrollment sits close to the California median campus size.
Its Resource Investment Index sits near the middle of the pack among 9,998 scored California schools.
Against 766 statewide peers matched on enrollment and economic need, it ranks mid-pack at #481.
Its student body is led by White (70%) and Hispanic or Latino (14%) (diversity index 48/100).
Counselor access is stretched at roughly 1055 students per counselor, well above the ASCA-recommended 250:1 ceiling.
15.6% of students were chronically absent in the 2021-22 collection, in line with the post-pandemic national range.
Among Petaluma's elementary schools, it stands alongside Mary Collins Charter School at Cherry Valley (494 students): Sonoma Mountain Elementary is smaller than that campus by headcount and runs leaner classes (26.4:1 vs 29.1:1).
Old Adobe Union also operates Loma Vista Immersion Academy (451 students) and La Tercera Elementary (295 students) alongside Sonoma Mountain Elementary.
Sourced from NCES CCD, CRDC, and F-33 (federal records, not a quality verdict). How we source and compute this.
Source: National Center for Education Statistics Common Core of Data + CRDC + F-33 · 2024-25
How Sonoma Mountain Elementary compares
Sonoma Mountain Elementary on the metrics families compare, against California and U.S. means.
| Metric | This school | vs California | California avg | U.S. avg |
|---|---|---|---|---|
| Students per teacher | 26.4:1 | ▲ 23% | 21.5:1 | 15.7:1 |
| Free-lunch eligible | 10.5% | ▼ 81% | 55.5% | 51.7% |
| Enrollment | 422 | top 57% | - | - |
Source: NCES Common Core of Data School-level CCD + state/national means from Public School Universe · 2024-25
26.4:1
Leaner classes than 4% of US schools, heavier class loads than most.
422
Bigger than 51% of US schools by enrollment, mid-sized for the country.
Equity indicators (what these measure)
Economic need
10.5%
free-lunch eligible
- 81% below the California average of 55.5%
Below the 40% Title I threshold, among the lower-need profiles in the state; federal aid targets individual qualifying students rather than schoolwide programs.
Staffing depth
26.4:1
students per teacher
- 23% above state mean
Top 87% in California - lower ratio than 13% of state schools
Well above 20:1, one of the more stretched staffing loads nationally relative to enrollment.
Engagement
15.6%
chronically absent (missed 10%+ of school days)
In the 15-20% range, nearing the "high" absenteeism threshold.
Funding equity
$15,370
per pupil, district-wide
- below California avg of $16,509
Somewhat below the U.S. average per-pupil spend; funding constraints may affect programs, facilities, and staffing.
Support staff
Counselors0.4 FTE
Student-support staffing from the Civil Rights Data Collection.
Discipline context
2
in-school suspensions + 4 out-of-school
Suspension rate: 0.5 per 100 students. Combined in-school and out-of-school rate: 1.4 per 100 students. Reported via the Civil Rights Data Collection.
Overview
- Common Core of Data (June 2026): enrollment, staffing, and the student-teacher ratio above.
- Civil Rights Data Collection: discipline counts and program access (AP, gifted, special education).
- F-33 School District Finance Survey: the district-wide per-pupil spending figures below.
Three separate federal collections, each on its own reporting cadence - which is why this school's numbers line up on a consistent basis against every other school and state on this site, rather than mixing figures pulled from different survey years.
Student demographics
White 69.7%
Hispanic or Latino 14.2%
Two or More 10.0%
Asian 5.2%
American Indian / Alaska Native 0.7%
African American 0.2%
Largest group: White at 69.7% of enrollment.
Student-body diversity index 48.1/100
Simpson diversity index - at 48.1, Sonoma Mountain Elementary is more mixed than the California school average of 46.0.
Programs
Gifted & talented Yes
Funding & spending
District-wide per-pupil expenditure for Old Adobe Union, which includes Sonoma Mountain Elementary.
$15,370
Per student
-7%
vs California
Avg $16,509
-7%
vs U.S.
Avg $16,593
Revenue mix
Local 54.9%
State 36.3%
Federal 8.8%
Source: NCES F-33 School District Finance Survey District-level finance · FY 2021-22 Per-pupil expenditure reflects the district-wide average. Individual school budgets are not reported at the federal level.
How Sonoma Mountain Elementary Compares to District-Mates
| School | Enrollment | Economic Profile | Student-Teacher Ratio |
|---|---|---|---|
| Loma Vista Immersion Academy | Similar size | Higher economic need | Lower S:T ratio |
| La Tercera Elementary | Smaller | Higher economic need | Lower S:T ratio |
| Miwok Valley Elementary Charter | Smaller | Higher economic need | Lower S:T ratio |
| Old Adobe Elementary Charter | Smaller | Higher economic need | Lower S:T ratio |
Comparisons are relative to Sonoma Mountain Elementary's own figures; each column derives from NCES Common Core of Data.
Other Schools in This District
- Enrollment
- 451
- Students per teacher
- 22.6:1
- Resource Index
- 24/100
- Enrollment
- 295
- Students per teacher
- 22.7:1
- Resource Index
- 29/100
- Enrollment
- 288
- Students per teacher
- 19.2:1
- Resource Index
- 36/100
- Enrollment
- 278
- Students per teacher
- 23.2:1
- Resource Index
- 33/100
Similar elementary schools in Petaluma
6 comparable elementary schools (grades K-5) serving the same city.
Mary Collins Charter School at Cherry Valley
Standard public school
494 students 29.1:1 students per teacher
Loma Vista Immersion Academy
Standard public school
451 students 22.6:1 students per teacher
Corona Creek Elementary
Standard public school
403 students 22.4:1 students per teacher
Grant Elementary
Standard public school
386 students 24.1:1 students per teacher
Meadow Elementary
Standard public school
384 students 24:1 students per teacher
Mckinley Elementary
Standard public school
368 students 24.5:1 students per teacher
Similar elementary schools statewide
Matched by enrollment size and by staffing ratio across all of California, not just this city - a different peer set than the local comparisons above.
Similar enrollment (~422 students)
Next steps
Verify locally before acting on Sonoma Mountain Elementary's federal record.
- Compare Sonoma Mountain Elementary against another school. Compare schools
- Old Adobe Union's spending and staffing shape this school. District profile
- Confirm current enrollment and boundaries with the school. Choosing guide
Federal record (CCD 2024-25, CRDC 2021-22) - PlainSchools assigns no subjective rating; the composite quality score is a transparent, reproducible index computed from this cited federal data.
Frequently asked questions about Sonoma Mountain Elementary
How many students attend Sonoma Mountain Elementary?
Sonoma Mountain Elementary has 422 students enrolled. It is an elementary school in Petaluma, CA.
What is the student-teacher ratio at Sonoma Mountain Elementary?
The student-teacher ratio at Sonoma Mountain Elementary is 26.4:1, which is 23% higher than the California average of 21.5:1 and 68% higher than the national average of 15.7:1.
What percentage of students receive free lunch at Sonoma Mountain Elementary?
10.5% of students at Sonoma Mountain Elementary are eligible for free lunch, compared to the California average of 55.5%.
What is the racial and ethnic makeup of Sonoma Mountain Elementary?
The largest demographic group at Sonoma Mountain Elementary is White at 69.7% of enrollment, in Petaluma, CA.
What is the Resource Investment Index for Sonoma Mountain Elementary?
Sonoma Mountain Elementary has a Resource Investment Index of 33/100 (typical reported resources relative to schools nationally) based on 4 factors: student-teacher ratio, counselor availability, attendance rates. Not a test-score or academic measure (national median ~41/100, see methodology).
How does Sonoma Mountain Elementary rank among elementary schools in Petaluma?
By Resource Investment Index, Sonoma Mountain Elementary ranks #15 of 25 elementary schools in Petaluma, CA. This compares federal resource and staffing data among local peers; it is not a test-score or academic ranking. See all elementary schools in Petaluma on the city page.
Is Sonoma Mountain Elementary a good school?
Sonoma Mountain Elementary earns 33/100 on the Resource Investment Index, with class sizes larger than 87% of California schools. This is a resource snapshot, not an academic rating; see the Resource Investment Index question above for what the number does and doesn't measure.
What other schools are in Old Adobe Union?
Besides Sonoma Mountain Elementary, Old Adobe Union also operates Loma Vista Immersion Academy (451 students), La Tercera Elementary (295 students), and Miwok Valley Elementary Charter (288 students). See the Old Adobe Union district page for the complete list.
Related tools
Every figure on PlainSchools is rendered directly from the source NCES, CRDC and F-33 federal records, no number is typed in by an editor. Each school's figures reflect its most recent NCES/CRDC submission on file. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of June 2026.