Twin Hills Charter Middle, Sebastopol CA

Original Research by School Decision on Twin Hills Charter Middle

Twin Hills Charter Middle is a small six-through-eight school located in Sebastopol, a compact wine-country city in Sonoma County. The school serves about two hundred students, evenly distributed across three grades, and operates as a charter school within the Twin Hills Union Elementary district.

Academic performance is uneven by subject. In English language arts, the school shows solid grounding, with sixth-grade proficiency near three-fifths and seventh and eighth grades both reaching about seventy percent. Math lags notably behind; sixth grade is substantially weaker at just over one-third proficiency, though seventh and eighth grade recover to around sixty percent. In science, the only grade tested, eighth-grade proficiency sits just below one-half. Overall, the school's average proficiency index places it in the top quartile among Sonoma County districts, reflecting strength in ELA that compensates for math and science challenges. A parent interested in math support should ask the school directly how it addresses sixth-grade gaps and what interventions or supports exist for students below proficiency in upper grades.

The student body is predominantly white, just over three-fifths of enrollment, with a quarter identifying as Hispanic. About one-quarter of students qualify for free or reduced-price lunch, suggesting moderate economic diversity. Data on the numbers of students with individualized education plans or English learners were not available. The school's enrollment is small, which shapes both its community feel and its resource constraints.

Sebastopol itself is a progressive, artsy town centered on a compact downtown with galleries, antique shops, farmers markets, and a mix of independent cafes and restaurants. The broader Sonoma County region is wine country. Schools in the area, including Twin Hills Charter Middle, sit on residential campuses away from the walkable downtown core, though the town and nearby rural areas are well-served by parks like Ragle Ranch and trail systems. Housing values are high for the region and have declined modestly in recent years; rental costs are also substantial. The local economy is small, anchored by professional services, education, and healthcare, with notable employers including the botanical-wellness company Traditional Medicinals and public schools.

The district recently passed a major facilities bond in June that will fund roof repairs, campus modernization, and security upgrades across its four schools, funded by an increase in property taxes. This reflects a need for facility investment and signals commitment to physical plant improvement over the coming years.

Charter schools in California operate with different governance structures than traditional public schools but remain publicly funded and tuition-free. This particular charter sits within a small elementary district in a tight housing market, so families choosing it are typically those already in or relocating to Sebastopol. A parent considering Twin Hills Charter Middle should understand its modest size, its uneven test performance with particular attention to sixth-grade math, and its role as one of a small cluster of schools serving a town with strong community identity but limited new housing supply and rising costs.

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Academic performance

How students perform on state tests, by grade, set against the district.

Math

Grade 637%

School 37% · District 46% · ▼ 9 pts below district

▲ 6 pts above state median · ▲ 2 pts above county median

Grade 762%

School 62% · District 60% · ▲ 2 pts above district

▲ 32 pts above state median · ▲ 31 pts above county median

Grade 862%

School 62% · District 58% · ▲ 4 pts above district

▲ 34 pts above state median · ▲ 32 pts above county median

English language arts

Grade 658%

School 58% · District 65% · ▼ 6 pts below district

▲ 14 pts above state median · ▲ 9 pts above county median

Grade 771%

School 71% · District 66% · ▲ 4 pts above district

▲ 25 pts above state median · ▲ 25 pts above county median

Grade 871%

School 71% · District 68% · ▲ 3 pts above district

▲ 26 pts above state median · ▲ 24 pts above county median

Science

Grade 849%

School 49% · District 48% · ▲ 1 pts above district

▲ 24 pts above state median · ▲ 22 pts above county median

Social studies

Grade 879%

School 79% · District 78% · ▲ 1 pts above district

▲ 30 pts above state median · ▲ 20 pts above county median

This schoolTwin Hills Union Elementary, same grade

Graduation rate (ACGR) reflects the federally published Adjusted Cohort Graduation Rate for the most recent year available. We refresh this data annually at the close of each academic year in June. The federal source publishes a banded rate (for example, "90-94%") instead of an exact number for cohorts small enough to risk identifying individual students. The state distribution chart, where shown, plots every school in the state with a published rate or band; schools whose rate is federally suppressed are excluded. Where the federal source publishes a band rather than an exact rate, the school is placed within its band using a stable, ID-derived offset, so its position is consistent across visits.

Proficiency by household income

English language arts

Grade 6Lower-income64%Higher-income57%8 pp gap

Grade 7Lower-income60%Higher-income73%13 pp gap

Grade 8Lower-income83%Higher-income63%19 pp gap

Mathematics

Grade 6Lower-income36%Higher-income37%1 pp gap

Grade 7Lower-income40%Higher-income67%27 pp gap

Grade 8Lower-income74%Higher-income55%19 pp gap