Altitude—vertical elevation above any given point especially above mean sea level.
Basin—a depression in the earth’s surface, as a valley, or the region drained by a river.
Bedrock—the solid rock underlying the looser materials of the earth’s surface.
Channel—the bed of a stream or any groove or passage.
Drainage—that which is drained off; waste water. In a drainage basin a large surface area whose waters are drained off into a principal river system.
Dredging—to clear or widen by means of a dredge.
Elevation—height above the sea level.
Geology—the science that treats of the origin, history, constitution, and structure of the earth, including the operation of the physical forces affecting its development and appearance and the history of living or extinct forms as recorded in the rocks.
Gradients—rising or descending gently or by degrees.
Outcrop—the exposure at or above the surface of the ground of any stratum.
Quadrangle—a tract of land as represented by the United States Geological Survey on one of its atlas sheets.
River—a large, natural stream of water, usually fed by converging tributaries along its course and discharging into a larger body of water.
Till—an unassorted, commingled, and chiefly instratified mass of clay, sand, pebbles, and boulders deposited by masses of ice.