Which river forms the northern border of West Virginia?

The Ohio River forms the northern border of West Virginia and plays a significant role in the state's geography and history. Stretching over 900 miles, it serves as a natural boundary between West Virginia and Ohio. This river was crucial for trade and transportation in the region, especially during the westward expansion in the 19th century. The historical significance of the Ohio River also includes its role in the establishment of state borders and its importance to various communities along its banks.

The other rivers listed do not define the northern boundary of West Virginia. The Cumberland River flows through Kentucky and is not associated with West Virginia's borders. The Tennessee River primarily runs through the state of Tennessee and does not impact West Virginia's geographical boundaries. The Potomac River, while important and located along the eastern part of West Virginia, particularly near Washington, D.C., serves as a border but does not extend along the northern edge of the state. Thus, the Ohio River is correctly identified as the river forming West Virginia's northern border.