Geodetic Base point for NAD 27http://en.wikipedia.org/wiki/North_American_Datum http://wikimapia.org/8808554/Meades-Ranch-Center-of-48-Stateshttp://www.ngs.noaa.gov/cgi-bin/ds2.prl?retrieval_type=by_pid&PID=KG0640http://www.photolib.noaa.gov/brs/cgind31.htm