Tuolumne County Sheriff's officials are asking for the public's help locating a missing woman, Patricia Sue Tolhurst, of Sonora.
Tolhurst, owner of Patty's Shack restaurant in East Sonora, was last seen Friday evening at her friend's house in Tuolumne.
Tolhurst sent a letter via U.S. mail, postmarked on Monday, telling her friends that she would be hiking, the report said.
Tolhurst was reported missing Tuesday by a friend.
Her car was found Wednesday at Donnell Vista, according to the report.
The Tuolumne County Search and Rescue team is looking for her in that area but, as of today, had not found her.
Anyone with information is asked to call 533-5815.