"I was afraid he'd been taken by a mountain lion. That has happened, even here in the East"
When and where? Haven't heard of a mountain lion attack in NC ever happening.
This is why you never give up looking.
There was a young child in a remote area of western VA who went missing several years ago. There was an immediate roadblock of all roads in the area, and there were so few roads that authorities felt no one could have escaped with the child. The concensus was that the boy had been taken by a lion.
I don't know if mountain lions are in North Carolina, but they travel tremendous distances, and if they are demonstrably in the mountains of Maryland and Virginia, quite close to people, they might possibly have made it to North Carolina by this time.