PRESCHOOL & SCHOOL: Upstate Montessori Academy 864.551.1152 Â 109 North Leach Street, Greenville, SC Upstate Montessori Website 2023 KABOOM Family Favorites Finalist: Private Schools Upstate Montessori Academy offers a Montessori education for students in 3K through 4th grade. 3K has a half-day or full-day programs, and 4K through 4th grade has a full-day program.