Austin Bohanan, 18, went missing while hiking with his stepfather in the Great Smoky Mountains National Park

A teenager who went missing in Tennessee's Great Smoky Mountains National Park for 11 days is now back with his family after he walked out of the park on Tuesday and flagged a passing boat for help.

Austin Bohanan, 18, became separated from his stepfather on August 11 while hiking and was reported missing August 13.

Even though he had a cellphone, he couldn't get a signal to call and ask for help.

Park spokeswoman Jamie Sanders previously said Austin had light food and water, but was not anticipating spending the night in the park.

After realizing he was lost, Austin tried to follow two creeks both upstream and downstream looking for the highway.

More than 100 searchers scoured a 6,700-acre area in the southeastern section of the park, aided by search dogs and a Tennessee Highway Patrol helicopter equipped with an infrared device.

Dense vegetation and blowdowns from previous storms make the search for the teen a painstaking process for Search and Rescue team members

Austin heard the helicopter at one point and tried to climb to where he could be seen.

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Austin's stepmother Brooke Bohanan embraces a Great Smoky Mountains Ranger after learning her stepson had been found

The Great Smoky Mountains National Park spans 6,700 acres in Tennessee

The teen eventually walked out of the backcountry on his own unharmed.

'We are so grateful for all the love, prayers and support from everyone,' said his aunt Carrie Bohanan.

His family had gathered near the site each day throughout the search.

'I serve an almighty God! Praise be given unto him!' Brooke Bohanan, Austin's stepmother, wrote on Facebook on Tuesday afternoon

Austin was assessed at Blount Memorial Hospital and released a few hours later.

He was found in remote Blount County, about 40 miles south of Knoxville.

Courtesy of WATE

More than 100 searchers scoured a 6,700-acre area looking for Austin (pictured). It is unclear what uniform he is wearing