JACKSON (WNE) — Yellowstone National Park search and rescue teams are switching into “recovery” mode and scaling back their efforts after 11 days of looking for Austin King.

The 22-year-old Minnesota man was last heard from on Sept. 17 when he called friends and family members from the top of Eagle Peak, which is in the remote southeastern corner of Yellowstone and is the highest point in the park.

King set out on a seven-day solo backpacking trip to the summit of Eagle Peak. The park initiated a search shortly after he did not show up for a boat that was set to pick him up on the southeast arm of Yellowstone Lake on Sept. 20.

Despite the park’s efforts, “We have not been able to locate Austin,” park Superintendent Cam Sholly said Wednesday in a press release.

“Although we will continue to hope for the best, I want to extend my deepest sympathies to Austin’s family, friends and colleagues,” he said.

Sholly thanked search and rescue teams that worked tirelessly in some of the most remote terrain in Yellowstone.

The park will continue with limited search efforts into the foreseeable future as conditions allow, the release said.

Over the summer, King worked for Xanterra Parks and Resorts, a private business that operates hotels and restaurants in the park. 

More than 100 personnel, two helicopters, dog teams, ground teams and drones have been involved in the search. They have found no definitive clues as to King’s whereabouts. Crews have searched more than 3,225 miles using helicopters and drones and on the ground at elevations ranging from 8,440 feet to 11,350 feet.

Yellowstone National Park does not expect to provide additional updates on the situation unless significant changes occur, Wednesday’s press release said.