An 85-year-old woman was found dead near her car in the Coachella Valley desert a day after she had called a friend to say she was lost, authorities said.

The woman's body was found Sunday night in Indio Hills along with her car, which was stuck in the sand, Riverside County Sheriff's Deputy Herlinda Valenzuela said.

The woman, whose name has not been released, called a friend in San Diego County Saturday night, and the friend received the message on Sunday morning. She called authorities at about 5:30 p.m. and they found the body about 20 minutes later.

Valenzuela said the coroner's office is working to find a cause of death.