A 33-year-old woman last seen camping at Glen Mervin Dam in Donnybrook is missing.
Gail Rose Grenfell, who has no fixed address, was camping with family at the dam but left about 2pm on Monday and has not been seen since.
It is believed she may have gone to Bunbury on Monday evening and could be in the Bunbury or Australind area.
She is thought to be in a depressed state of mind.
Ms Grenfell has fair skin, a medium build and black hair that is usually tied in a pony tail.
She was last seen wearing black jeans, a blue tank top and a silver necklace and she could be carrying plastic bags with more clothes.
Anyone who gave Ms Grenfell a lift from Glen Mervin Dam to Bunbury or who has any other information is asked to call Crime Stoppers on 1800 333 000.