Marking the junction of Grant, Preston and Tucker Counties, the Fairfax Stone is 2 miles off US 219, 4 miles north of Thomas, West Virginia.  The stone is one of the oldest markers in the United States.  In 1681 Charles II of England granted Lord Hampton 6 million acres in this area.   The grant was inherited by Lord Fairfax in 1722.

Sitting at the source of the north branch of the Potomac River, where three counties converge upon the southern tip of Maryland, the Fairfax Stone comes as near as anything to being a cornerstone for the whole state. Some of the earliest surveys in West Virginia started from the point and some historians believe that the original stone may have been set by George Washington, a surveyor in his youth.  The spot marks the boundary between Maryland and West Virginia and the headwaters of the Potomac River.

Fairfax Stone State Park, a 4-acre West Virginia State park, is located just off of Route 219 north of Thomas, WV.