Its northern border is the Potomac River, while its southern border is an intangible line running from the southern terminus of the Short Hill to the base of Catoctin Mountain, located approximately two miles north of Virginia State Route 7.

The valley contains the communities of Waterford, Lovettsville, Wheatland, Morrisonville and Taylorstown.

The valley was settled in the 1730s by German and Quaker immigrants who migrated south from southern Pennsylvania.

This region of Loudoun stood in stark contrast to the southern Loudoun Valley and areas east of the Catoctin Mountain, where plantation-style farming was established by English settlers moving north out of Tidewater Virginia.

As a result, early in the war, fierce partisan fighting broke out between the area's Unionist soldiers, the Loudoun Rangers and the county's pro-Confederate soldiers, at The Fight at Waterford.