South Branch Mountain is a mountain ridge that runs southwest to northeast through Hampshire and Hardy counties in the Eastern Panhandle of the U.S. state of West Virginia, rising to its greatest elevation of 3,028 feet (923 m) above sea-level in the Nathaniel Mountain Wildlife Management Area. South Branch Mountain is among the largest and most prominent of the mountains in the Ridge-and-valley Appalachians of the Eastern Panhandle region. It forms the eastern edge of the South Branch Potomac River Valley from Springfield to Moorefield.