How long is the extension of the blue ridge mountain range that Nichol's Gap Road was built over?
Nichol's Gap Road:  The highway was built over the South Mountain (Maryland and Pennsylvania) via Nichol's Gap ( ) and down the Devils Racecourse into the Cumberland Valley, allowing access to the 1762 Hagerstown, Maryland. South Mountain (Maryland and Pennsylvania): South Mountain is the northern extension of the Blue Ridge Mountain range in Maryland and Pennsylvania.
i don't know