Complex sentence: Pequenakonck Elementary School, located away from the middle school/high school, serves grades K-5, and the North Salem Middle School, which shares the same building with the high school, serves grades 6-8.
Split into simpler sentences: Pequenakonck Elementary School, located away from the middle school/high school, serves grades K-5. The middle school, which shares the same building as the high school, serves grades 6-8.