Cantwell-Sacred Heart of Mary High School (CSHM), is a private Roman Catholic high school located in Montebello, California, precisely on the border of East Los Angeles and Montebello. It is now owned and operated by the Roman Catholic Archdiocese of Los Angeles. It is fully accredited by the Western Association of Schools and Colleges and the challenging curriculum prepares students for admission to four-year university programs and other career options.