Mill Creek Mountain is a continuous mountain ridge that runs northeast through Hampshire and Hardy counties in the Eastern Panhandle region of the U.S. state of West Virginia. Rising to its greatest elevation of 2,650 feet (808 m) at High Knob, Mill Creek is a folded mountain ridge, belonging to the Ridge-and-Valley Appalachians. Mill Creek Mountain forms the western edge of the South Branch Potomac River Valley and is named for Mill Creek that carves through it at Mechanicsburg Gap allowing the Northwestern Turnpike (U.S. Route 50) to pass through as well.