A body believed to be that of a missing Oregon hiker has been found in Wrangell-St. Elias National Park and Preserve this week, with few details available on how he died.

A statement from the park said the apparent remains of 34-year-old Nick Larsen were found Wednesday on the Nizina River. Larsen, an experienced hiker who had last been seen Aug. 7 in McCarthy before embarking on a solo backpacking trip, was the subject of a ground search which was called off last week.

Jamie Hart, a park spokeswoman, said efforts to find Larsen had resumed after rafters on the river Monday discovered his backpack. Search-and-rescue teams found the body, which had tattoos matching Larsen’s, on a nearby bar of the river.

“He was found near about a mile downstream from the historic Nizina Bridge,” Hart said.

It wasn’t immediately clear how long the body had been on the river bar, Hart said, or whether it exhibited any obvious signs of trauma.

The Park Service offered its condolences to Larsen’s family and friends in the wake of the discovery. Hart said the state medical examiner’s office in Anchorage has received the body, which will be autopsied to determine a cause of death.