If this is what I think it may be it would be extremely far east into the Sierra from what I would normally expect. This species guess is on the basis of the extreme phenotypic variation of the leaves, lack of yellowish pubescence on the underside (as occurs on nearby Quercus chrysolepis) and the smooth white bark on even some of the larger branches. The area has a known human presence dating back hundreds or even thousands of years, so translocation of an acorn of this species from lower elevations is entirely possible. Interested to hear thoughts.