I like to plan trips wherever I go. This morning I'm compiling a list of Northern California places of interest.
LAKE SHASTA CAVERNS NATIONAL NATURAL LANDMARK What can I say? Forest, lake, cave (I do like caves!) It's a bit of a trip, but looks like it could be worth it. The only problem is, they may not take my National Parks Pass, because National Natural Landmarks could be under private ownership. Certainly the website is privately owned, although there is a listing for the site in the NPS page.
Lava Beds National Park lava tubes! Bats! Lava fields!
Muir Woods (so long as I don't run into any talking apes!)
There's also some really oddball stuff in the far northwest corner of the state, up around Eureka, including The Trees of Mystery, The Bigfoot Museum, and the Tour Through Tree, but those are a heck of a drive for a day trip.
I'll definitely plan on Petaluma Adobe State Park, and look forward to some sort of involvement with Windrush Farm, the local wool farm. In anticipation of that, I think I'll probably make myself a new malacate.