That map obviously wasn't official, but it was fairly accurate except for the exaggerated claims of coverage past the coastal mountain range.
Not official? Somebody ran over to the Mobil station, grabbed a free road map, cut out a chunk of it, circled the lower Bay Area with a ballpoint pen, taped it to some fancy KFMR letterhead and xeroxed it, and you don't think that's an official coverage map? How dare you, sir!!!
The page referenced in Dave's post has been updated:
http://www.bayarearadio.org/stn_documents/kfmr_coverage-map_c1975.shtml