Valley Oak at Crane Creek regional park in Sonoma County California.
The mid-afternoon light was flat, and I think I will come back and photograph this tree from the other side.

Something I never noticed before, but makes sense if you think about it: as I walked around the park, I noticed that for every tree, if I stood where you could see the trunk and branches then I was looking into the sun. Of course the leaves grow and spread out more on the side of the tree that faces the afternoon sun!