Either a rogue (jay-planted?) Q. kelloggii well outside any nearby grove, or more likely, a live oak-black oak hybrid (photo taken in late January)
This is a hybrid oak with Q. kelloggii and Q. agrifolia parentage. Note that the architecture and bark more resemble Q. kelloggii, while leaves are closer to Q. agrifolia, although the leaves carry the larger size and longer spiny lobes of the Q. kelloggii.