From Mendocino north California is at risk also.
My wife was a manager at PG&E before retiring, and had spent some time at their facilities at the Geysers electrical generation plant (before they forced the company to divest it). Stinky sulfur smells and hot steam gushing forth from hot magma under the ground. So yes, north California is at risk but primarily from volcanic activity. When the big one rips in the Cascade fault, upper Northern California will also get hit, and hopefully not trigger any volcanoes. The coastline up north will feel the Tsunami (Crescent City comes to mind).