Potomac Wastershed
TThe Potomac River has its head at Fairfax Stone, which the extreme southwestern corner of Maryland and which marks the point from which the western boundary of Maryland was surveyed. It follows in a northeasterly direction for a distance of about 100 miles until it join the South Branch. The South Branch rises in Highland County, Virginia, and flows northeastward for a distance of 200 miles to its junction with the North Branch near Green Spring, WV, in Hampshire County. At that point the Potomac flows eastward and then southeastwardly for a distance of about 100 miles to Harpers Ferry, WV, and from there flows southeasterly into the Chesapeake Bay south of Point Lookout, in Virginia.

The drainage area of the Potomac River is about 14,500 square miles, of which 3,480 square miles, or 24 per cent, are in West Virginia.

Some of the featured rivers and streams of the Guyandotte Watershed are:
- South Branch of the Potomac River
- South Branch of the Potomac River ( Smoke Hole)
- Cacapon River
- Lost River
- Shenandoah River
- North Branch of the Potomac River
- North Branch of the South Branch - Hopeville Canyon