Zion National Park, Utah (1951)

Open All Year
UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary
NATIONAL PARK SERVICE Arthur E. Demaray, Director
Zion National Park, located in the heart of the spectacular desert and canyon country of southern Utah, has as one of its chief features the great multicolored gorge, Zion Canyon. The sandstone cliffs, rising sheer to form the canyon walls and encircle the valley, are awesome; but it is the vivid coloring which most amazes. The deep red of the Vermilion Cliffs is the prevailing tint. Two-thirds of the way up these marvelous walls and temples are painted varying shades of red; then, above the reds they rise in startling white, sometimes surmounted by a cap of brilliant red.
Zion Canyon, the best known example of a deep, narrow, vertically walled chasm readily accessible for observation, was made by the north fork of the Virgin River, the stream which now flows through it. Before this stream established its course there was no canyon. During the long period since its course was established the river has slowly deepened its channel and extended it headward until its original shallow valley has become a long narrow trench between towering walls. Though now deeply entrenched in the rocks of the Kolob Plateau, the river maintains substantially its original pattern. It flows in the same direction, and the curves and straight stretches of its present walls duplicate the meanders of the stream when it flowed some 5,000 feet above its present level.
For many thousands of years the Virgin River and its tributaries have been busy with two tasks, namely, deepening their channels and transporting material weathered from the canyon walls. At present the Virgin carries away from the park each year about 3,000,000 tons of ground-up rock at an average rate of 180 carloads a day. For such effective work the many-branched river seems incompetent. But though relatively small in volume, this stream system falls from 50 to 70 feet per mile (nine times the fall of the Colorado in Grand Canyon) and is at work on rock, chiefly sandstone, that disintegrates with exceptional ease. Many tributaries are on bare rock, little retarded by vegetation, and are fed by short but violent showers. Consequently, they are brought to flood stage not only seasonally but with each period of heavy rainfall. Because they flow only in response to showers, the smaller tributaries are unable to cut channels as deep as the perennial master stream. From their mouths high on the canyon walls, they descend as waterfalls.