(Portland, OR)  --  Authorities say the search for a Portland man who's been missing since Saturday has been suspended.  Officials say 68-year-old Thomas Branch McAdams, who recently displayed signs of memory loss, vanished after going into the Columbia Gorge around Horsetail Falls.  Officials say his vehicle was found Sunday near Horsetail Falls.  Through yesterday, searchers had covered about 200 miles of trails in the search for McAdams.