Keystone Montessori began in 1981 as a small program located at Sycamore Congregational Church and was called "Cerrito Vista Montessori." Its current Spanish-style home on Blake Street was built for the school and opened in 1995. It serves children from 18 months through kindergarten. The school is affiliated with the American Montessori Society. A 10% sibling discount is offered on a second child's tuition.