Authorities say a body has been recovered from the Colorado River in Grand Canyon National Park and it’s believed to be that of a California man reported missing from a commercial river trip last month.

Park rangers say the body was recovered Wednesday below Lava Falls, transported to the rim by helicopter and transferred to the Coconino County Medical Examiner’s office for positive identification.

Based on evidence found with the body, park officials say the body appears to be that of 66-year-old Peter Francis Schwab of Healdsburg, California.

Schwab was last seen on June 28 after a sightseeing day hike at National Canyon on the Colorado River.

The National Park Service conducted a multi-day search and rescue operation and is investigating the incident.