Ava Zechiel, a 16-year-old from the District who vanished during a hike in the Tennessee mountains, has been found safe. (National Center for Missing and Exploited Children)

Authorities in the Tennessee mountains found a District teenager alive and well Tuesday after she went missing last week on a group hike through a national forest with her school.

Ava Zechiel, 16, was on a rugged trail when she vanished about 2:30 p.m. Nov. 11. Ground and air searches by the Johnson County sheriff and the FBI turned up no clues of her whereabouts, frustrating and frightening her family and friends.

But the search continued, and Zechiel was found somewhere in the woods around lunchtime Tuesday, according to her relieved father, Howard Zechiel, who was in Tennessee.

“She was found by the search teams in good health,” he said, adding that she was on her way to the county fire station.

A little while later, her mother posted on Facebook that her daughter couldn’t walk and was being carried out of the woods. However, she was “healthy enough” to see her parents before being taken to a hospital.

“You can’t imagine my joy,” she wrote.

Johnson County Sheriff Mike Reece did not immediately return a request for comment.

Zechiel, a former student at Wilson High School in the District, attends Freedom Mountain Academy in Mountain City. It bills itself as “a rare alternative boarding school with a focus on providing a comprehensive program that combines academic study, farm work and wilderness adventure.”

Zechiel’s father would not comment on the circumstances of his daughter’s disappearance, but Dan Cullinane, a staff member at the school, told The Washington Post that she ran away after refusing to hike any farther.

Staff members on the hike began a search and called 911, Cullinane said. The group was about two miles from the nearest town and even closer to roads when Zechiel vanished.

Her friends and family started a Facebook group called “Help Us Find Ava Zechiel.” A flier posted by the National Center for Missing and Exploited Children was also distributed, saying that Zechiel may be in need of medical attention.

“Praying this is the day Ava is found,” the Facebook group posted Monday, “as the search continues this morning.”

This was not Zechiel’s first hike.

A few days before she went missing, Zechiel wrote a blog post on the school’s Web site about an earlier trek. (The site is down, but a cached version is available.)

Nothing appeared to be amiss.

“Coming from a large city to a farm in Northeast Tennessee was a shock to my system and so was my first expedition,” she wrote, adding, “Hiking has never been my forte.”

She said the hike lasted six days and included “descending a rocky trail and a visit to a small plane crash site.”

“Although my first expedition was one of the hardest things I have ever done, I can already see that it has helped. . . . ” she wrote. “For one, I have become a lot more confident in my abilities, and I feel happier for having pushed myself through hard times successfully.”