Bay Area Math Circle - Features The Bay Area Mathematical Olympiad (BAMO) and weekly program for San Francisco Bay Area high and middle school students. - http://mathcircle.berkeley.edu/
Stanford Math Tournament - Annual math event sponsored by the Stanford Mathematics Department. Site contains results, past tests and solutions. - http://www.stanford.edu/group/sumo/smt/
Santa Clara University High School Mathematics Contest - An annual High School Mathematics Contest usually scheduled on the second Saturday in November. This is a three hour exam which tests problem solving skills and mathematical ingenuity. - http://math.scu.edu/activities/hscontest.html
Bay Area Math Meet - Annual, all-day competition featuring both individual and team events. the core events include Math Bowl and Test of Ingenuity. Website contains detailed description, past exam, and results. - http://www.usfca.edu/math/bamm/