Mary Institute and Saint Louis Country Day School or "MICDS" is a secular, co-educational, private school home to more than 1,200 students ranging from grades Junior Kindergarten(age 4) through 12, including a separate "lower school" for children in Junior Kindergarten through Grade 4 known as the Ronald Beasley or "Beasley" School, the MICDS "Middle School", spanning grades 5 through 8, and the "Upper School", consisting of grades 9 through 12. Its 100 acre (404700 m²) campus is located in the St.