The body was found on a 10-acre parcel of undeveloped private property between Petaluma River and Schooner Landing Park at about 2:30 a.m., police Lt. Tim Lyons said.
Authorities have not released any information about the person's possible identity.
Police made the discovery about 45 minutes after receiving a report of a body possibly seen in the area, Lyons said. Detectives summoned to the scene combed the area searching for clues
The Sonoma County Sheriff's Coroner removed the body and will conduct an autopsy to help identify the body and possibly determine a cause of death, Lyons said.
The police investigation will include review local open missing persons cases and interviews with those frequenting the area.
Anyone with information about this incident is asked to call the Petaluma Police Department at 707-778-4372. If you wish to remain anonymous you may call PPD Crime Tips at 707- 781-1200 or email firstname.lastname@example.org.