Mike, I've been puzzling over your query and it finally came to me why Holly Swamp sounded so familiar.  I'm thinking this property is around the Powellville area.  I say this because Elisha Pennewell sold 30 acres of it to John Truitt in 1769 and the property remained in the Truitt family for several generations.  A friend of mine descends from these Truitts and his greatuncle was called "Holly Swamp" because of living on that piece of land.  Holly Swamp supposedly stood 6'7", which was a giant in those days.