TRUCKEE, Calif. — There was no foul play in the death of a 16-year-old whose disappearance sparked a weeks-long search effort before her body was found in her car submerged in a Northern California reservoir, authorities said Thursday.

The body of Kiely Rodni, of Truckee, was found Aug. 23 by a volunteer dive team. She was last seen alive Aug. 6 at a party of hundreds of youth at a campground at Prosser Reservoir in Tahoe National Forest, about 165 miles northeast of San Francisco.

The Nevada County Sheriff’s Office said in a statement the coroner ruled Rodni’s death accidental.

“This ruling is based on the pathologist’s finding that her death was the result of drowning and that there was no other information to suggest she was the victim of foul play,” the sheriff’s office said.

Rodni’s disappearance triggered a huge search by multiple law enforcement agencies over two weeks, including underwater searches of the reservoir by dive teams.

Volunteer searchers with a sonar-equipped group called Adventures with Purpose found Rodni’s car, a silver 2013 Honda CR-V, upside down with a body inside in about 14 feet of water in the reservoir, about 55 feet offshore.

How she ended up in the water is under investigation by the California Highway Patrol’s major accident investigation team.

The toxicology report identified ethanol, nicotine, caffeine, cotinine, and delta-9-carboxy-THC in Rodni’s system.

The area has curvy roads, and photos of the area where the car was pulled out of the reservoir show a wide expanse of bare shoreline that appears to gradually slope toward the water.