Barker Ranch is infamous as the last hideout of Charles Manson and his "family" during and after the gruesome LA murder spree. It is located inside Death Valley National Park in eastern California.
Recently (Early 2008), forensic investigators have searched the ranch with "cutting-edge forensic technology" and turned up possible graves of undiscovered Manson murder victims.
http://www.iht.com/articles/ap/2008/03/15/america/CSI-Manson-Ranch.php
the ranch was not built by the family... it was a previously abandoned filming lot that Manson aquired through his family contacts.