AMBOY, WASHINGTON (BNO NEWS) — A human skull had been found at a travel-trailer site in Washington, local police said Sunday.

The skull was discovered Saturday at the well-known Lake Merwin Camper’s Hideaway Campgrounds in Amboy, Washington.

Authorities do not believe that foul play was involved or that this is a homicide case. The most likely cause of death would be drowning in the nearby Lake Merwin or by slipping along its rocky shore, according to Clark Counry Sheriff’s Office Public Information Officer Steve Shea.

Sergeant Shea believes that the skull had been at the campground for an extended period of time.

The Clark County 9-1-1 Dispatch Center was notified of the find early Saturday by a resident of the campground.

Lake Merwin Camper’s Hideaway is a 588-acre member-owned camping ground which leases space to people who own recreational vehicles and campers and moorage for up to 56 boats and watercraft. A small private beach is also available for swimming.

Investigators from the Sheriff’s office will return to the Amboy campground later this week to thorougly search for additional bones.