The 20-year-old Hispanic man from Redwood Valley, whose name has not been released, is presumed drowned, according to the Mendocino County Sheriff's Office.
Sheriff's officials reported that they and the Army Corps of Engineers received a report of a possible missing person at Lake Mendocino just after 8:30 a.m. Tuesday.
Deputies and Corps of Engineers rangers contacted Paul Hansen, who reported the missing man, at the lake.
Hansen told officials that he and the victim had been camping along the western shore line near the old winery area.
They had a small motor boat which drifted off the shoreline and Hansen believed the victim attempted to swim out to the boat – about 40 yards east of the campsite – to bring it back to shore and drowned in the process, the sheriff's office reported.
Deputies and corps rangers began a search of the shore line with the corp boat, while Cal Star helicopter conducted an aerial search of the area. The searches yielded no sign of the man.
Mendocino County Sheriff's Search and Rescue divers also started an underwater search.
Officials noted the investigation is continuing.
