https://www.mercurynews.com/2020/03/18/bay-area-parks-and-beaches-whats-open-during-coronavirus-shutdown/

Because the shelter-in-place order allows outside exercise, most parks in the San Francisco Bay Area are allowing public access to trails, beaches and other open space.

Visitor centers and other buildings are closed. Visitors are reminded to maintain at least 6 feet distance from other people, except members of their own households.