A fall line is the imaginary line between two parallel rivers, at the point where rivers plunge, or fall, at roughly the same elevation.

Fall lines are often located where different elevation regions, such as coastal and piedmont, meet. They are important to people and businesses. The fall line is the point at which boats traveling upriver usually cannot continue any further. It is also the point at which hydroelectric power generation may be possible, taking advantage of the energy of the waterfalls.

In the eastern United States, there is a major fall line between the hard rock of the Appalachian Piedmont and the soft sediment of the Atlantic Coastal Plain. This line was important to early European explorers because it marked the limits of river travel for ships. Many cities developed along this fall line, including Trenton, New Jersey; Richmond, Virginia; and Philadelphia, Pennsylvania.

fall line
These waterfalls represent a fall line, the imaginary line where at least two rivers plunge at the same elevation. The falls here are actually part of the same river.
Noun

edge of land along the sea or other large body of water.

Noun

low, flat land lying next to the ocean.

Noun

height above or below sea level.

Noun

imaginary line along which parallel rivers plunge, or fall.

hard rock
Noun

dense rock that is difficult to crack or break. Usually igneous or metamorphic.

hydroelectric power
Noun

usable energy generated by moving water converted to electricity.

parallel
Adjective

equal distance apart, and never meeting.

Noun

area at the bottom of a mountain.

Noun

solid material transported and deposited by water, ice, and wind.

upriver
Adjective

toward or near the source of a river.

Noun

flow of water descending steeply over a cliff. Also called a cascade.

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