Grand River Dam Authority Police identified the body found floating in the lake Wednesday afternoon.
The GRDA said the body was that of Zachary Butler, 27, of Tulsa. Butler had been reported missing by the Tulsa Police Department on July 29, 2016.
Butler's body was found floating in the Drowning Creek arm of Grand Lake on Wednesday afternoon.
A joint investigation by the GRDA and the Oklahoma State Bureau of Investigation is in progress.