JACKSON (WNE) — Rangers and Search and Rescue crews still have not found Austin King, the hiker who last made contact with the outside world a week and a half ago on a remote peak in Yellowstone National Park.

As of Friday afternoon, efforts to locate the 22-year-old were continuing, seven days after they began.

Spokesperson Linda Veress didn’t indicate on Thursday when the search would stop. 

On Thursday, the park used two helicopters — one belonging to Yellowstone, and the other belonging to Teton County Search and Rescue — to continue searching the Eagle Peak area. Officials said they will continue searching drainages and ridgetops near the 11,372-foot peak, the highest in the park.

Park rangers were also working with cellular forensics experts to learn from King’s cellular activity the evening of Sept. 17 on Eagle Peak. King called his friends and family from the peak the same day.

To date, 96 people have been involved in the search, Yellowstone officials said. They’ve used two helicopters, a search dog team, ground crews with spotting scopes and a drone to look for the hiker.

King is from Winona, Minnesota. This summer, he was employed by Xanterra Parks and Resorts, the private business that operates hotels and restaurants in Yellowstone. 

Greg Jackson, a former National Park Service ranger who retired in 2013 as deputy chief of national law enforcement, said there are a number of unknowns regarding King’s disappearance.

For example, King’s camp was found southeast of the peak. Why he left it is unclear.

“Under what circumstances would you leave your camp?” Jackson said. “Most people wouldn’t leave their survival supplies on purpose.”