The remains of a 72-year-old man from Los Angeles who vanished in the Grand Canyon more than six months ago were believed to have been found this week, National Park Service officials said Thursday.

A river rafting group was on a day hike up the Monument Creek drainage on Wednesday when they discovered human remains. Rangers went to investigate and said there was evidence indicating they were likely those of Raafat “Ralph” Nasser-Eddin, who was reported missing on June 13, according to a news release on the Grand Canyon National Park’s website.

Nasser-Eddin was last seen two days prior, on the morning of June 11, near Hermit Camp on the Hermit Trail. But an intense multi-day search of the area in the extreme Arizona heat of late spring yielded no clues or information into the missing man’s whereabouts, officials said.

The remains were found about 2.5 miles away from his last known location, according to the website.

The Coconino County Medical Examiner’s Office is still working to confirm the person’s identification, and no additional details were immediately available.