A human skull recently discovered in Flathead Lake is believed to be that of a Native American man who died long ago, and no crime is suspected in his death, the Lake County Sheriff's Office said Thursday.

In a news release, the sheriff's office said an anthropologist enlisted by the Montana Forensic Science Lab determined the skull is "archeological, or historical in nature, and thus not belonging to a modern human."

The sheriff's office previously said operators of a gill-netting boat discovered the skull in a net while pulling it from the water on the afternoon of June 23.

Based in part on observations of the teeth, the anthropologist determined the man most likely was between 30 and 60 years old when he died, the sheriff's office said. It wasn't immediately clear how old the remains are believed to be. The detective assigned to the case was not available for comment Friday.

The sheriff's office said it was working to repatriate the remains to the Confederated Salish and Kootenai Tribes, which may seek additional DNA testing.

Assistant editor Chad Sokol may be reached at 406-758-4439 or [email protected].