A 69-year-old California man died last weekend at Arches National Park, after he disappeared from a group tour along the Delicate Arch Trail.

Kaize Peng of San Francisco was found dead at about 1:30 a.m. on Sunday, June 19, about 150 meters off the popular trail.

The tour group first reported that Peng was missing at about 7:45 p.m. on Saturday, June 18. At the time, no one in the group had seen him for about three hours, according to the Grand County Sheriff’s Office.

With the help of Grand County Search and Rescue team members, Arches National Park workers initiated a search for Peng. Classic Lifeguard and Utah Department of Public Safety helicopter crews assisted in the search, and the helicopter team located him early the next morning.

Authorities transported Peng’s body to the Utah Office of the Medical Examiner in Salt Lake City. The cause of his death is unknown at this time, the sheriff’s office reported.