Simplify the following text for a Grade 7 native English-speaking person.
Original: The source of the North Branch Potomac River is at the Fairfax Stone located at the junction of Grant , Tucker and Preston counties in West Virginia .
Simplified: The North Branch starts at Fairfax Stone in West Virginia , and the South Branch starts in Highland County , Virginia . The North Branch and the South Branch meet in Hampshire County , West Virginia , and make the Potomac River .