Hillcrest Christian School: Preschool, Elementary School, Middle School, High School. Thousand Oaks, California. Ventura County, California. Accredited Christian School Hillcrest also offers an English Language Development Program. HCS is authorized under federal law to enroll non-immigrant students by issuing I-20 forms in grades 3 through 11. For homeschool families, Hillcrest offers Satellite Saints, a program that supports homeschool families.