If traveling central California, then you might want to visit the Benitoite Mine near Coalinga California. The road is a bit winding and narrow in places, but the country is beautiful and peaceful.
Benitoite: The Rarest Gemstone Found Only in California Benitoite: The Rarest Gemstone Found Only in California
Another interesting trip in this region is the New Idria ghost town. It is abandoned and free. The road is paved to within about the last mile. The last mile is very rough. Boondocking is free.
A great companion book for a visiting New Idria is: https://www.amazon.com/s/ref=nb_sb_n...ining+District