Manson and his followers used Barker Ranch as a hideout after the killings of several people in and around Los Angeles, including pregnant actress Sharon Tate.
The only items found by the 20-member search team before the search ended Wednesday include a .38-caliber shell casing, ash and animal remains, the Los Angeles Times reported Thursday.
"They're excavating the last area. That will be the last one. We'll be finishing up at this site and that will be it for the day," said Inyo County Sheriff Bill Lutze.
Authorities said four sites at the ranch seemed likely to have human remains after search dogs and investigative equipment showed signs of biological deterioration.