The Bay Area keeps inching closer and closer towards that light at the end of the COVID-19 tunnel. Beginning Tuesday, San Mateo County will join San Francisco in the yellow, least restrictive tier. The President of the San Mateo Board of Supervisors, David Canepa announced the decision. California as a whole is doing great in the fight against COVID-19. The 7-day positivity rate is 1%, the lowest since the pandemic began.