Prior to 1994, high school students belonging to the
San Gabriel Unified School District (SGUSD) attended
San Gabriel High School, which is part of the
Alhambra School District, since SGUSD did not have a high school of its own. In April 1992, San Gabriel residents won the right to educate their own high school students by ballot measure, winning 61% of votes to establish an autonomous school operated by the SGUSD. In response, the
Alhambra School District (ASD) filed a lawsuit alleging that the
California Board of Education had improperly excluded Alhambra voters and because ASD stood to lose as much as US$1.8 million in state funding, since the planned high school would siphon away 1,400 students. Homeowners in San Gabriel also led the opposition to a bitterly disputed bond measure, claiming they would fight the district's attempts to raise the funds necessary to build the high school, which would be temporarily situated at the site of the old
Jefferson Middle School campus. On September 8, 1994, Gabrielino High School opened its doors to its first class, teaching 9th graders. Alhambra School District retained responsibility to school 10th to 12th graders until 1995, as part of an agreement signed by both districts in June, the same month Alhambra filed its lawsuit. The school's site on Lafayette Street formerly housed Jefferson Intermediate School, which was moved to the location of the former Madison Elementary School north of Las Tunas Road. In June 1994, the
Los Angeles Superior Court ruled in favor of Alhambra, declaring that the 1992 election was unconstitutional because all the stakeholders had not been allowed to vote in the measure. On March 20, 1999, an arsonist set a US$2 million fire that destroyed 2 offices and 10 classrooms, effectively displacing 400 of the 1,400 students on campus. On December 5, 2011, the San Gabriel Unified School District Board voted 3-2 not to renew the contract of Sharon Heinrich, the school's principal, for 2012–2013 school year, citing concerns about her leadership and supervisory abilities, against the opinion of Gabrielino alumni, students and faculty. On January 9, 2012, the Board reversed its previous decision, following the swearing-in of a new board and community outcry. == Architecture ==