Never been to Blue Ridge myself but big black cat sightings along that corridor go back decades. There's a cluster of reports from the Shenandoah stretch that I've been tracking since the early 2000s - witness accounts, one decent plaster cast of a print that measured out at roughly 5 inches across. Way too big for any domestic or feral cat.
The frustrating thing is the terrain out there makes it almost impossible to get solid photographic evidence. Dense canopy, low light, and these animals seem to avoid open ground whenever possible.
What direction were you travelling? And roughly what time of day? The afternoon sightings tend to happen near the overlooks where deer congregate, which makes sense from a predator standpoint. If you can give me more detail on the colouration - was it a flat matte black or did it have any sheen to the coat in direct light - that actually matters quite a bit for narrowing down what you might have seen. Some witnesses describe what turns out to be a melanistic bobcat, which is rare but documented. Others are describing something significantly larger.