Best Public Schools in Custer, SD

Three schools in Custer, South Dakota, serve students from prekindergarten through grade 12: Custer Elementary (269 students), Custer Junior High (101), and Custer High School (272), all in Custer School District 16-1. Together they enroll 642 students. The clearest shared strength is math: in 2025–2026, the elementary and junior high averaged 63% proficient, compared with 44% statewide, an advantage of 20 percentage points.

Custer Elementary stands out in the comparable all-grades results, leading Custer Junior High by 5 percentage points in ELA (57% versus 53%) and 11 points in math (69% versus 58%). Both were above state results, but the elementary school’s advantages were larger: 8 points in ELA and 25 in math, compared with 4 and 14 points at the junior high. There are important grade-level exceptions: grade 3 ELA at the elementary school was 35%, 8 points below the state, and grade 8 ELA at the junior high was 45%, 7 points below. Custer High School’s 2025–2026 ACT results were mixed against the state: grade 11 math was 6 points higher, while ELA and science were each about 1 point lower; these ACT results should not be compared directly with the other schools’ Smarter Balanced results.

Compared with 2024–2025, the two comparable schools’ average advantage over the state narrowed in ELA, from 14 to 6 points, but widened in math, from 16 to 20 points. Science also declined in the reported same-grade comparisons: grade 8 at Custer Junior High fell from 73% to 53%, while grade 5 at Custer Elementary moved from 66% to 63%; both remained above state results. SchoolDigger’s percentile ranking changed from 67 to 83 for the elementary school, 76 to 79 for the junior high, and 82 to 49 for the high school, though ranking pools differ by year. In 2024–2025, student-teacher ratios ranged from 10.3:1 at the elementary school to 13.7:1 at the high school; all three reported free/reduced lunch eligible figures for that year, ranging from 27% to 34%. Chronic absenteeism also differed: 7% at the elementary school versus 26% at the junior high in 2025–2026.