A fisherman called the sheriff's office at 1:00 p.m. Saturday when he found a child's body floating in the lake near Farm to Market Rd. 3286 and County Rd. 310.
Approximately an hour and a half later the body of a man was found in the same area.
The medical examiner's office has identified the victims as David Edmondson, 59, and his 9-year-old grandson Noah Pell, both of McKinney.
Both victims were wearing life jackets and a 15-foot canoe belonging to the victims was also found in the area.
Investigators believe the pair went to the lake early Saturday morning.