Mill Creek is a 14.0-mile-long (22.5 km)[1] tributary stream of the South Branch Potomac River, belonging to the Potomac River and Chesapeake Bay watersheds.[2] The stream is located in Hampshire County in West Virginia's Eastern Panhandle. Mill Creek flows into the South Branch west of Romney Bridge near Vanderlip along the Northwestern Turnpike (U.S. Route 50).