It may have changed since I lived there but that was certainly true when I did. And I spent a lot of time rambling around the mountains, creeks, and NFs and NPs there and most all of it bushwhacking off trail.
I was bit by a tick in Marin a few years ago (I caught the tick as well), got very nervous about Lyme and researched it thoroughly, was much less concerned after consulting a few folks in the Bay Area. Lyme seems rare here (UCSF estimates 2-15% prevalence in ticks but its far less common than on the east coast).