Will, this is a very interesting record and fly. It must be L. trux - although the large silver patch of hairs that trux typically has (just in front of the scutellum) is not very evident in your photos. Laphria trux is mainly a Southern California fly (and spectacular looking when seen alive!) - found in Chaparral and dry forest vegetation in mountains from Sta. Barbara Co. southward to San Diego Co. - so your Central California record is unusual. I haven't seen other L. trux specimens from this far north; maybe fewer silver hairs is due to geographical variation?