Caribou County Sheriff Ric L. Anderson says three anglers in a boat on Tuesday spotted an empty boat with its motor running moving in circles.
About 100 yards away they found an elderly man in the water.
Anderson tells the Idaho State Journal (http://bit.ly/1meIqzL) that the anglers pulled the man into their boat and called authorities, then met emergency responders at a dock.
The man didn't survive.
Anderson says the man might have been camping near the reservoir.
The man's name hasn't been released.
Information from: Idaho State Journal, http://www.journalnet.com