Authorities say a man drowned at the Oroville Wildlife Area near Palm Avenue in Gridley while trying to cross a pond carrying a rock.
Twenty-one-year-old Austin Harr was reportedly attempting to swim across a pond Monday while holding a rock estimated to weigh about 10 pounds.
His friends called for help when he did not emerge from the water.
It's unclear why Harr was swimming with a rock, although California Highway Patrol says alcohol may have played a role.
Sarah Bohannon contributed to this report.