Mason County Coroner Wes Stockwell identified the dead boy Sunday as Jace S. Olsen and his father as Sheldon W. Olsen, 31.
Officials were alerted to possible trouble at about 6:48 p.m. Saturday when they received a 911 call from the boy's mother, Julie Olsen, saying that her son and her husband were overdue from a canoe outing on the lake. The family lives in a home on the lake shore.
Deputies and search teams responded to the scene, where witnesses told them that the two were seen in a canoe on the lake offshore from the clubhouse as late as 6:13 p.m.
The witnesses later saw the unoccupied canoe still on the lake, floating free, and the alarm was sounded, said Mason County Sheriff Dean Byrd.
Mason County sheriff's deputies organized a search immediately using one of the department's three boats and divers, and Jace's body was found floating on the lake at about 9:20 p.m. Saturday. He was not wearing a life jacket.
The search continued for the little boy's father until midnight, when it was called off. Searchers resumed their efforts at 9 a.m. Sunday, this time using sonar gear in the murky lake, but still no sign of the father has been found.
Deputies have not discovered any signs of foul play and characterized the incident as a father-and-son outing that turned tragic, Byrd said.
Two life jackets were found in the empty canoe, leading investigators to conclude life jackets were not used by either victim.
Byrd said Sheldon Olsen had recently finished optometry school, and his family had just moved to this area from Portland, Ore., after he found a job here.
Saturday was Julie Olsen's birthday, and the father had taken his son out for a canoe ride on the lake because he wanted to give his wife a break and let her get some rest. But when they didn't return she realized something was wrong.
Bishop Steve Taylor of the Church of Latter-day Saints said the family was active in the church and both often volunteered with youth at the church. Their son, Jace, was adopted.