I plan to ride in all the counties of California, all 58 of them. I would like to drive my SUV to the most northern part first, and then on separate occasions, do the others in some systematic way.
Looking at the map, There's Del Norte, Siskiyou, Modoc, Humboldt, Trinity, Shasta, and Lassen. Would these 7 be workable in 7 to 10 days? I would drive to a hotel or motel, then ride in the most scenic or ridable roads for 4 hours of riding, then kick back and relax and then drive to the next destination.
Looking south from there, the counties are much smaller in area and I figure I could do a quite a few more in the same amount of time. But that would be on a separate trip.