High Quality Content by WIKIPEDIA articles! San Tomas Aquinas Creek, known locally as San Tomas Aquino Creek, is a 16.5-mile-long (26.6 km) stream that heads on El Sereno mountain in El Sereno Open Space Preserve in Saratoga, California in Santa Clara County, California, United States. It flows north through the cities of Saratoga, Monte Sereno, Los Gatos, Campbell, Santa Clara and San Jose before its confluence with the Guadalupe Slough in south San Francisco Bay.