LINN COUNTY, Kan. -- Volunteers will continue to search Tuesday for a missing man.

Relatives said Richard Clark, 67, has Alzheimer's disease. Clark was last seen walking down the driveway from his family home in Pleasanton Sunday evening.

Family members told KMBC they think Clark was going to try to walk to his old home in Kansas City. It's also possible he could have hitched a ride, but relatives said they're really concerned Clark is stranded in the country without food or shelter.

Clark is 5 feet 9 inches tall and weighs 185 pounds. He was wearing a black shirt and blue jeans. Anyone who sees Clark can call the Linn County Sheriff's Department at (913) 795-2665.