The visitor seeing Palo Duro Canyon for the first time may find it
difficult to believe that this yawning chasm began as a simple gully.
But to the _geomorphologist_—the geologist who studies the origin and
development of landscapes—Palo Duro Canyon is but a gully magnified many
times over. This is evident because the shape of the canyon, the nature
of its tributaries, and the character of its walls indicate that it has
been deepened and lengthened by the downcutting of a stream and widened
by other geologic processes.