Summary:
Castlewood, South Dakota, has four schools serving 345 students from pre-K through grade 12: Castlewood Elementary - 02, Castlewood High School - 01, Castlewood Middle School - 03, and Claremont Colony Elementary - 04. In 2025–26, Claremont’s all-grades test results are suppressed, so the clearest comparison is between Elementary and Middle. The most important finding is their sharp difference: Elementary is above state proficiency rates in both reported subjects, while Middle is below them, with the biggest school-to-school gap in math.
Castlewood Elementary stands out in the current all-grades results: 57% are proficient in ELA, 8 percentage points above the state, and 65% in math, 21 points above. Castlewood Middle is below the state in both subjects, with 42% proficient in ELA (7 points below) and 33% in math (11 points below). Elementary leads Middle by 15 points in ELA and 33 in math. Castlewood High also has positive results: its 11th-grade ACT proficiency is above state rates in ELA, math, and science by 8, 9, and 5 points, respectively.
Recent results show improvement at Middle but declines at Elementary: from 2024–25 to 2025–26, Middle gained 3 points in ELA and 4 in math, while Elementary fell 10 points in ELA and 8 in math. Elementary’s strong current results have an exception in fifth-grade science, at 16%, 26 points below the state; the year before, it was 48%. SchoolDigger ranks High 34th of 130 schools (74th percentile, 4 stars), Elementary 78th of 203 (62nd percentile, 3 stars), and Middle 108th of 151 (28th percentile, 1 star). Student-teacher ratios are 13 at Elementary, 16.2 at High, and 18.2 at Middle. For 2024–25, the free/reduced lunch eligible measure is 26% at Elementary, 18% at Middle, and 14% at High; Claremont’s 21% figure is from 2022–23, so it is not a same-year comparison.
Thank you for your feedback!