Now, San Francisco police have discovered a woman's body in a Lombard Street hotel and the couples' car abandoned near Devil's Slide on Highway 1.
Police confirmed the body was that of Colleen Waterman, but have not yet released the cause of death.
Her husband Billy Waterman is now a person of interest, according to police.
The couple was first reported missing on Monday. Both the body and the car were found Thursday.
Police said Billy Waterman is 6 feet tall, white, 51 years old and weighs 160 pounds. He has blue eyes and red, balding hair.
Anyone with information about his location is asked to call the sheriff's office at 650-363-4911 or the anonymous San Francisco police tip line at 415-575-4444.