Yes, although it appears to be the part of the trail west and south of his home in Centreville, and it is legendary.
I think, as usual, much isn't being said.
To go very far from his home, eg to Maine or Georgia, he'd need to fly or drive. Flights are easy to rule out.
Possibly his vehicle never left his home. Wouldn't there otherwise be a BOLO for the vehicle or, if found, more certainty about where he'd gone?
The theory from the coworkers might be: maybe he took a taxi to get to the nearest trailhead.
I don't know anything about the trail north of Shenandoah, but perhaps it isn't as hard to search as the park.
JMO