Early this week hunters following a deer blood trail discovered a human skull on state game land; off of State Road, about a half mile south of Birch Road. After the discovery the hunters contacted the police. Deputies and Detectives with the St. Clair County Sheriff's Department responded to the location. A search of the immediate area revealed more human bones. Sheriff Tim Donnellon says the Medical Examiner has the bones and that the Michigan State Police is also assisting in the investigation. Sheriff Donnellon says they are also doing research into missing person cases in St. Clair county and bordering counties. Investigations in the case are still continuing.