Sheriff's investigators were on Horse Island off Sackets Harbor late Thursday afternoon, after "partially decomposed" human remains were found.
In a statement, Sheriff Colleen O'Neill said a state parks employee discovered the clothed remains of an adult in a wooded area of the island at 11:20 AM.
The Jefferson County Medical Examiner's Office was notified, and ordered the body taken to Samaritan Medical Center's morgue, where it will be examined to determine who the person was and how he or she died. A detective said the death appeared to be a suicide.
A number of sheriff's office personnel were in Sackets Thursday investigating.