Searchers prepare to board a helicopter atop Eagle Pass in Yellowstone National Park while searching for a lost hiker last seen on Sept. 17. (NPS Photo/Jacob W. Frank)

Officials in Yellowstone National Park are scaling back efforts to find a missing hiker after 11 days of searching a remote corner of the park.

More than 100 people have been searching around Eagle Peak, in Yellowstone’s southeast corner, for Austin King, a 22-year-old male, who was last heard from on Tuesday, Sept. 17, when he called friends and family from the summit of Eagle Peak.

Search efforts included the use of two helicopters, search dog teams, ground teams with spotting scopes, trackers, and a drone, according to a statement released by the park’s public affairs office. Search and rescue workers have covered more than 3,225 miles by air and ground at elevations ranging from 11,350 feet to 8,400 feet. Efforts have yet to yield any definitive clues as to King’s current whereabouts.

King, an employee of Xanterra Travel Collection, the park’s primary concessioner, failed to arrive for his boat pickup near Yellowstone Lake’s Southeast Arm on the afternoon of Sept. 20, after his planned 7-day solo backcountry trip to summit Eagle Peak, the highest point in Yellowstone National Park.

Limited search efforts will continue into the foreseeable future as conditions allow.

“Despite significant search efforts over the past week and a half, we have not been able to locate Austin,” said Superintendent Cam Sholly. “Although we will continue to hope for the best, I want to extend my deepest sympathies to Austin’s family, friends and colleagues.”

“I also want to thank the teams from Yellowstone and Grand Teton national parks, and Park and Teton counties, Wyoming, who have all worked tirelessly to find Austin in some of the most difficult and remote terrain in Yellowstone,” Sholly said.

The park does not expect to provide further updates unless a notable change occurs.