Long proposed and supported by the NEDA-Regional Development Council-Cordillera, it as one of twelve defined metropolitan areas in the Philippines. The original "BLIST" long existed as a concept since its inception in August 1990, a month after the 1990 earthquake which devastated the city of Baguio and other surrounding areas, and only existed as an informal reference to the area. The concept was later amended into "BLISTT" in 2009, which included the municipality of Tublay, despite not being adjacent to the city of Baguio. It was officially established after a signing of a memorandum of agreement by the mayors of the component local government units.