Gateway STEM High School is a public magnet high school in St. Louis, Missouri, USA.HistoryGateway opened as John O'Fallon Technical High School in 1956, named in honor of John O'Fallon. Under its former name it opened in August 1992, in response to a court order mandating the establishment of a high technology magnet school.The school ultimately integrated now closed high schools Health Careers and the Academy of Mathematics & Science ((covering English, social studies, math, and science, respectively)(defensive tackle). Sam Scarber - San Diego Chargers (running back