The case of a missing Hawthorne woman last seen in the Sierra Mountains three months ago has been turned over to the FBI.

Officials say the August disappearance of Nita Mayo has been re-classified as a case of a "missing person with suspicious circumstances."

They aren't releasing details about the decision to change the classification.

Mayo told a friend the morning she was last seen that she planned to drive through Sonora Pass for a daylong shopping trip.

Mayo's car was discovered with her purse, cell-phone and keys inside around Donnell Vista on Highway 108 shortly after she disappeared.

Searchers and family members last scoured the area in October. They're planning another search this weekend to focus on the Hawthorne area.