SEATTLE » A teenage girl who survived a small-plane crash in the craggy, thickly forested mountains of north-central Washington state emerged from the wilderness after hiking "for a couple of days" and was picked up by a motorist who drove her to safety, authorities said Monday. But the fate of her two step-grandparents, who were also on board, remained unclear.

David Veatch, the father of 16-year-old Autumn Veatch, told reporters outside a Brewster hospital late Monday his daughter is exhausted but doing remarkably well.

She was able to joke with him about all the survival shows they watched together on television, he said.

"She’s just an amazing kid," he said. "There’s more to her than she knows."

The teen has no life-threatening injuries but is dehydrated and suffering from a type of treatable muscle tissue breakdown caused by vigorous exercise without food or water, Three Rivers Hospital CEO Scott Graham said. She was kept at the hospital overnight for hydration and rest.

The Beech A-35 left Kalispell, Montana, Saturday afternoon, headed for Lynden, Washington. Also on board were Leland and Sharon Bowman of Marion, Montana.

Navy helicopters searched for the plane wreckage until late Monday night, several hours after fixed wing planes suspended their search for the night. The search will resume on Tuesday, weather permitting, said Barbara LaBoe, a Washington state Transportation Department spokeswoman.

Rescuers earlier narrowed down a search area based on cellphone data and typical flight patterns. But there was no sign of the aircraft or its occupants until the teen followed a trail to state Route 20, near the east entrance to North Cascades National Park.

A motorist picked her up Monday afternoon and drove her 30 miles east to a general store in Mazama, where employees called 911. The Aero Methow Rescue Service sent a paramedic team to check her out before she was taken to the Brewster hospital.

Okanogan County Sheriff Frank Rogers said Monday afternoon that the girl had been "walking for a couple of days." He called her feat "pretty impressive."

Serena Lockwood, the manager at the Mazama Store, said the girl and a motorist came in Monday afternoon, saying she had been in a plane crash.

"She was obviously pretty traumatized," Lockwood said.

Rescuers celebrated Veatch’s survival, but they immediately returned their focus to finding the wreckage, aided by Veatch’s description of the crash site, said Lt. Col. Jeffrey Lustick of the Civil Air Patrol. Lustick said he could not confirm any details about the condition of the grandparents.

"We’re so happy about this," Lustick said. "I’ve spent 30 years in the Civil Air Patrol and in search-and-rescue. Moments of joy like this can be hard to find."

Lustick said he had spoken with Veatch’s father, who said his daughter told him the plane crashed and caught fire after flying into a bank of clouds. She remained at the crash site for a day before deciding to hike down, eventually finding a trail and following it to the trailhead on Highway 20.

The crashed plane crossed the Idaho-Washington border about 2:20 p.m. PDT Saturday, but it dropped off the radar near Omak, Washington, about an hour later, transportation officials said.

Associated Press writer Phuong Le contributed to this report.