• 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.

    Photograph by Jamal Harrell, MyShot

    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.

  • Term Part of Speech Definition Encyclopedic Entry
    coast Noun

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

    Encyclopedic Entry: coast
    coastal plain Noun

    low, flat land lying next to the ocean.

    Encyclopedic Entry: coastal plain
    elevation Noun

    height above or below sea level.

    Encyclopedic Entry: elevation
    fall line Noun

    imaginary line along which parallel rivers plunge, or fall.

    Encyclopedic Entry: fall line
    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.

    piedmont Noun

    area at the bottom of a mountain.

    Encyclopedic Entry: piedmont
    sediment Noun

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

    Encyclopedic Entry: sediment
    upriver Adjective

    toward or near the source of a river.

    waterfall Noun

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

    Encyclopedic Entry: waterfall

For Further Exploration

Articles & Profiles

Tell us what you think