The Merced County Sheriff's Office responded to the state park Sunday afternoon for a report of a man who had possibly drowned.
Deputies say the man went into the water but was not seen for several minutes.
The Stanislaus County Sheriff's Office Air Support Unit could not locate him from the air, leading to the Merced County Sheriff's Office Water Rescue and Recovery Team being requested.
Rescue divers were able to find the man in the water and pull him out.
The man was later pronounced dead at the scene. He has not been identified.
Deputies want to remind everyone to be cautious and to wear a life jacket when swimming.