The crash occurred near the banks of the Fraser River about eight kilometres west of the lake, which is approximately 250 kilometres northwest of Kamloops.
The Joint Rescue Coordination Centre were alerted to the incident around 8.30 p.m. PT, four hours after the man was expected to return.
Air Search Co-ordinator Cpt Hugh Kennedy says rescuers located the float plane after their aircraft picked up an emergency locator transmission just before 11:30 p.m. PT.
The victim was the only occupant of the float plane. His name has not yet been released.
The Transportation Safety Board is investigating.
Below is a map of all fatal aviation crashes that have occurred in British Columbia.