When we did our Central Coast California unsupported tour, we stayed mostly at State Parks..COuld not go wrong..California park's usually have a special section for cyclists. And the space is below regular camp site costs , since cyclists are not dragging in a car - which is using up space.
A nice State park camp site for cyclists was under $5. To choose otherwise and not have camp site ammenities..WOuld not make sense to me...
ALong the California coast, state parks are everywhere...Plus, The parks assure cyclists they will have a spot to camp.