File:Allegheny Front South of Williamsport, Pennsylvania (7238135558).jpg

The Allegheny Front is the major southeast- or east-facing escarpment in the Allegheny Mountains in southern Pennsylvania, western Maryland, and eastern West Virginia, USA. The Allegheny Front delineates the Ridge-and-Valley Appalachians to its east from the Appalachian Plateau (locally called the Allegheny Plateau) to its west. The Front is closely associated with the Appalachian Mountains' Eastern Continental Divide, which in this area divides the waters of the Ohio/Mississippi river system, flowing to the Gulf of Mexico, from rivers flowing into Chesapeake Bay and from there into the Atlantic Ocean. However, the Front and the Divide do not always coincide; for example, the North Branch of the Potomac River begins well west of the Allegheny Front, at the Fairfax Stone near the southwestern tip of Maryland. The Allegheny Front is one of the windiest spots east of the Mississippi, leading to the recent establishment of wind farming there.

en.wikipedia.org/wiki/Allegheny_Front