Police are conducting a land and air search for a missing prospector, about 30km north of Collie.
John MacKay, 70, set out with a friend near the Bell Brook/Toorak Roads area in Yourdamung Lake around 5pm on Sunday when they became separated.
Police are currently searching the area along with SES volunteers and personnel from the Department of Biodiversity, Conservation and Attractions.
Two helicopters are also searching for Mr MacKay.
The 70-year-old is described as light skinned, approximately 181cm tall, with a solid build, moustache and white hair
He was last seen wearing dark clothing, a wide brimmed hat and steel capped boots.
Concerns are held for his welfare and anyone who sees him, or has information regarding his whereabouts is asked to contact police on 131 444.
PIC: Google Maps