Fall zone

The Fall Zone is the geographic boundary between the Piedmont and Coastal Plain physiographic provinces of the Eastern United States. Often called the Fall Line at small scales (large areas), this zone of falls or rapids at the edge of the Piedmont lies upstream from the tidal rivers of the tidewater region. Examples of the Fall Zone include the rapids in Richmond, Virginia, where the James River falls across a series of rapids down to the tidal estuary of the James River.