[1] As of October 2007, it served 17,331 students and had 997 teachers, and served the cities of Burien, much of Des Moines, Normandy Park, and SeaTac as well as adjacent unincorporated census-designated places proximal to Burien in King County such as White Center and much of Boulevard Park.

[2] Highline consists of four main "service areas", Evergreen (the area around White Center), Highline (in Burien), Mount Rainier (mainly Des Moines, but includes parts of Burien), and Tyee (SeaTac), which once represented the district's four high schools.

In the mid-2000s, Highline commenced a major effort to reverse its schools' declining performance.

The most significant aspect of this effort was the conversion of Evergreen and Tyee into three small schools each.

Highline and Mount Rainier underwent similar programs, however each remains a single comprehensive high school.