Investigators first assumed he walked to the trail and may have been somewhere up on Kennesaw Mountain. But a search and rescue team with three dogs was back Tuesday morning in some of the most remote parts of the park.
And after five days: nothing.
Blake's mother Neill saw him last Wednesday night and said he was his normal, calm, easy-going self.
"He said, 'Love ya mom, see ya later' like we always do,” Neill Blake said.
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His mom, dad and older brother call it completely unexpected and said David would never just walk off.
"No one, roommates, coworkers, family had no inkling we would be standing here,” said David Blake’s dad, Bill Blake.
The avid hiker and outdoorsman is very familiar with the Kennesaw National Battlefield Park and the more than 16 miles of trails.
"He knows the area very well,” Bill Blake said.
Cobb police said David Blake’s hiking bag was still in his car.
"If he were doing that he would have taken some of that gear, and his apartment, all his camping gear is all still there,” Neill Blake said.
And his family said David wasn't into any high-risk behaviors, or illegal activity.
"That's not David,” Neill Blake said.
His family called him quiet and relatively boring.
"All they do is stay up till 3 a.m. playing their video games, watching movies, no indication anything was going on from that perspective,” said Stuart Blake, David Blake's brother.
That's why the mystery deepens after each day and hour, while his mom has this plea:
"Please be on the lookout for him. My concern is he's hurt up there, on the mountain somewhere and we need to find him,” Neill Blake said.
David Blake's phone was last used to send some text messages early last Thursday. He never showed up to work that day and didn't call in. Since then, there's been no activity on his phone or from his bank or credit cards.