BRYCE CANYON A Geologic and Geographic Sketch of Bryce Canyon National Park

A GEOLOGIC AND GEOGRAPHIC SKETCH OF BRYCE CANYON NATIONAL PARK

THE PINK CLIFFS

The Pink Cliffs rank first among the great walls that give the scenery of southern Utah its unique expression. It is the longest, the most continuous, and the most prominent of all the plateau escarpments and the most extensively and intricately carved. As the rim rock of the High Plateaus, it extends almost continuously from Cedar City eastward to Paria River and northward beyond the Fremont River, a distance of over 150 miles, and within the plateau are borders the Sevier River nearly 50 miles. As the top step in the series that includes the Chocolate Cliffs (Moenkopi), the Vermilion Cliffs (Chinle), the White Cliffs (Navajo), and the Gray Cliffs (Cretaceous series), the Pink Cliffs are perched high in the air, on the sky line as seen from most view-points in northern Arizona and southern Utah. Everywhere they are bold and impressive, and their grandeur is enhanced by their strong color and their amazing display of architectural form. In the words of Dutton, "the glory of all rock work."

The distinctive feature of Bryce Canyon National Park is the system of canyons cut into the rim of the Pink Cliffs that abruptly terminate the Paunsaugunt Plateau; groups of canyons that combine to form alcoves, large, isolated canyons, and narrow slits—each with its peculiar sculpture, alinement, and form. Of the alcoves in the "rim rock," the best known and the most accessible is at the head of Bryce Canyon, but the heads of Black Birch, Aqua, Bridge, Sheep, Yellow, and Willis Canyons are no less attractive. As viewed from points along the park rim road, each of the score of tributaries to Paria River rises in an amphitheater a few hundred feet deep and wide. Some of the great recesses resemble bowls in which for a short space the side has been broken down to permit the escape of its contents. None of these bowls is flat-floored or bordered by sheer walls. From their bottoms rise spires and ridges, and many of them are filled to the brim with literally thousands of towers, needles, cathedrals, high, narrow mesas, and myriads of fantastic figures that stand alone or are grouped about buttresses of the enclosing walls, which themselves are decorated with windows and niches of many shapes. Every erosional feature possible to make in rocks of this kind seem to be represented by innumerable examples.

In the forest-like array of erosional forms, individual components at first go unnoticed; they seem to be lost in the amazing landscapes. Yet their wealth in numbers is matched by richness of architectural form. Some pinnacles are ribbed and flutted so symmetrically as to seem to be the work of powerful lathes; some are rounded like huge stalagmites, others are nearly square; some rise from the canyon floor but most have been carved in the sides or at the top of the walls; some are isolated, others are grouped in companies; some terminate as flat caps; some form domes, others extend upward as spires and minarets. Some of the larger towers are bordered by sheer walls but commonly they are horizontally grooved and decorated with bosses and statues. (See Fig. 4, 5, 10).

Like the form, the color of the Pink Cliffs ranges widely. The top beds are white, gray, or cream colored; those below are dominantly red of various shades, grading into delicate pink and orange. more rarely into yellow, pale lemon, purple, or brown. Integrading and strongly contrasted interbanding are common, and in places one color is thinly overlaid by another. The color changes tone with passing clouds, with the direction of illumination at sunrise, sunset, and noonday, and when wet by infrequent showers. Days of wandering in the canyons and along their rims give the impression that in the morning when sunlight strikes directly against the walls the mass tone is orange and yellow, at noon grades into pink, and in the shadows of sunset is an inspiring display of delicate reflected lights. In moonlight, the coloring of the weird "ruined cities" is fascinating.

Bryce Canyon (and the other rim canyons) is an outstanding illustration of local erosion. It might naturally be supposed that the great alcove had been carved by waters pouring down from the plateau above. But the plateau streams contribute nothing; from the very rim they flow in an opposite direction. The sculpturing agents are the snow and rain that fall directly into the canyon, and the transporting agents are tiny intermittent streams less than 5 miles long. In fact, all of the park below the plateau rim has been carved by forces near at hand, and which may be seen in operation every day.