Harbor Ridge Middle School 9010 Prentice Ave, Gig Harbor, WA98332 Located on Prentice Avenue, Harbor Ridge Middle School has one of the best views of the harbor and Mount Rainier in the…More area. Formerly known as the Union High School, the building was built in 1921. The school completed its most recent remodeling project in 2006 and currently features 14 classrooms, four science labs and a computer lab for its students. Serving more than 500 students, Harbor Ridge is one of four middle schools in the Peninsula School District. It offers several athletic programs and after school clubs in which the school provides a free activity bus.