Put this road on your bucket list and do it in the winter or early spring. Florescent green and gold as far as the eye can see. Massive Valley oaks, the largest oak tree in the world, rolling hills and granite outcroppings.
Allow 5 days to do it right.
https://en.wikipedia.org/wiki/California_State_Route_49
Hell, if you HAVE to do it in the summer you can see the Jumping Frog Jubilee of Calaveras County.
I have done Highway 1(101) from Santa Cruz to Seattle 3 times by motorbike, never gets old.
The Gold country is wonderful too...a bit hot for me.
The Frog Jump Jubilee is held during the Calaveras County Fair in early May. The grass will still be green in early May this year. I used to take my kids when they were little and they loved it.