Allegheny Plateau
![Map of the Allegheny Plateau. The gray line differentiates the glaciated (northern) and unglaciated (southern) sections of the plateau.](/Images/godic/202412/18/Alleghenyplateaumap0144.png")
![Major fault at the dividing line between the Allegheny Plateau and the true Appalachian Mountains in Williamsport, Pennsylvania](/Images/godic/202412/18/Junction_fault_01120144.jpg")
![Canisteo River Valley from Pinnacle State Park. Glaciation in this area of the plateau removed the sharp relief that is seen in unglaciated areas of the plateau. The line of the distant peaks approximates the level of a peneplain that was uplifted to form the plateau.](/Images/godic/202412/18/Canisteo_valley_14530144.JPG")
The Allegheny Plateau /ˌælᵻˈɡeɪni/ is a large dissected plateau area in western and central New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Ohio. It is divided into the unglaciated Allegheny Plateau and the glaciated Allegheny Plateau.