 The westernmost valley, the Alleghany Valley, is narrow and situated between Allegheny Mountain to the west and Lantz Mountain to the east.It is drained by Back Creek, a tributary of the Jackson River, in the southern section of the county and is drained by Straight Fork to the north.The Laurel Fork runs to the west of Alleghany Valley, joining the Straight Fork in Pendleton County, West Virginia to the north to form the North Fork South Branch Potomac River.