Part 3

The desert climate has combined with the nearly flat lying layers of sediments of different character, hardness, and thickness to produce steep slopes having many cliffs and ledges and generally sharp to angular edges rather than the subdued rounded forms of more humid regions. This has led geologists to refer to such terrain as having “layer-cake geology,” and this is brought out by the profile in the rock column (fig. 9), by the cross section (fig. 10), by figure 15, and by many of the other photographs. But the baker of this cake was rather careless—not only do the layers range widely in thickness and character, but some are wedge shaped, thick on one side of the cake but thin or absent on the other. Then too, when he ran out of icing in the midst of a layer, he was apt to finish with a different kind or color, for no inspector was on the job to insure orderly construction.

If all the rock strata in the park were present at one locality, their sequence and thickness would be those shown on the right-hand side of the graphic section in figure 9. However, because of the lateral changes in thickness and character and the wedging out of certain beds, such as the White Rim Sandstone Member of the Cutler Formation, no two sections of the strata are exactly alike. This will be brought out in photographs of different exposures of rocks in various parts of the park.

An often-asked question is, why are most of the rocks so red? This can be answered by one word—iron, the same pigment used in rouge and in paint for barns and boxcars. Various oxides of iron, some including water, produce not only brick red but also pink, salmon, brown, buff, yellow, and even green or bluish green. This does not imply that the rocks could be considered as sources of iron ore, for the merest trace of iron, generally only 1 to 3 percent, is enough to produce even the darkest shades of red. The only rocks in the park that contain virtually no iron are white sandstones of the White Rim Sandstone Member of the Cutler Formation (figs. 21-24) and the Navajo Sandstone.

As pointed out by Stokes (1970, p. 3), microscopic examination of the colored grains of quartz or other minerals shows the pigment to be merely a thin coating on and between white or colorless particles. Sand or silt weathered from such rocks soon loses its color by the scouring action of wind or water, so most of the sand dunes and sand bars are white or nearly so.

The map (fig. 1) and cross section (fig. 10) of the park show that in general the major features of the landscape lie at three different and distinctive levels. A recently erected plaque on Grand View Point appropriately refers to these levels as the “Three Worlds.” The high plateaus, or mesas, in and adjoining the park dominate the skyline—in fact, the central one, between the Green and Colorado Rivers, is appropriately named Island in the Sky. If you stand on either the east or the west shore of this towering cliff-bordered island, you can look across a sea of fantastic erosional forms to a similar cliff-bordered shore at about the same level. Closer inspection of the sea of rocks on either side shows relatively flat benches or platforms about halfway to the bottom; below these are the generally steep sided or cliff-bordered canyons of the two rivers and their larger tributaries. From some vantage points along the shore, such as Dead Horse Point (fig. 15) or Green River Overlook (fig. 23), you can see the deepest level of all—the channels and flood plains of the Green and Colorado Rivers.

What caused the “Three Worlds” and the formidable cliffs supporting the high mesas or forming towering monoliths like Angel Arch or Druid Arch (figs. 43, 54)? Differences in the composition, hardness, arrangement, and thickness of the rock layers determine their ability to withstand the forces of fracturing and erosion and hence their tendency to form cliffs, ledges, or slopes. Most of the cliff- or ledge-forming rocks are sandstones consisting of sand grains deposited by wind or water and later cemented together by silica (SiO₂), calcium carbonate (CaCO₃), or one of the iron oxides (such as Fe₂O₃), but some hard, resistant ledges are made of limestone (calcium carbonate). The rock column (fig. 9) shows in general how these rock formations are sculptured by erosion and how they protect underlying layers from more rapid erosion. The nearly vertical cliffs supporting the highest mesas consist of the well-cemented Wingate Sandstone protected above by the even harder sandstone of the Kayenta Formation. To borrow from an earlier report of mine (Lohman, 1965, p. 17),

Vertical cliffs and shafts of the Wingate Sandstone endure only where the top of the formation is capped by beds of the next younger rock unit—the Kayenta Formation. The Kayenta is much more resistant than the Wingate, so even a few feet of the Kayenta * * * protect the rock beneath.

In some places remnants of the overlying Navajo Sandstone make up the topmost unit of the cliff.

How to See the Park

The question of how to see the park has no simple answer, for the park is too vast and complex to comprehend by a quick visit to any one of its many and varied parts or by any one means of transportation. Some, as did Major Powell, view it only from the rivers—by boat plus a few back-breaking climbs up the bordering canyon walls. Others see only the small parts reachable by passenger cars. The more venturesome see vastly more by jeep, foot, or horseback. And a few prefer to view it as the birds do—from the air. Many, those who put aside their magazines long enough, get bird’s-eye views without half trying, for Canyonlands is beneath the principal air routes connecting Los Angeles with Grand Junction and Denver. Actually, a full appreciation of all the wonders and beauties of the park is possible only by combining all these approaches and methods of locomotion, but only a few fortunate souls such as Bates Wilson have thus been able to inspect virtually every square foot of it.

The task clearly before me, then, is how best to present such a complex wonderland to you, the reader. The method I selected, after considerable thought and a few false starts, is to begin at the top—the high mesas—and work my way downward much as the rivers have done in carving out this fantastic area, to some of the broad benchlands beneath the mesas and eventually to the river channels and deep canyons. Although the approach I selected may not be the best, and admittedly is but one of several that comes to mind, I hope it gets the job done.

The High Mesas

Even though the “peninsular” mesas east and west of Island in the Sky, known respectively as Hatch Point and the Orange Cliffs, lie outside the present boundaries, they provide breathtaking views of important features within the park, so brief descriptions of them are included below. But first, let us take a closer look at Island in the Sky.

Island in the Sky

As the map (fig. 1) shows, Island in the Sky is really a fork of a wedge-shaped peninsula extending southward between the two rivers. An outlier to the south named Junction Butte has already been severed from the main peninsula by erosion and now is a true island. (See frontispiece and fig. 22.) A large chunk of Island in the Sky south of The Neck was about to be severed by erosion from the main peninsula to become a true island, when recent widening and grading of the road gave it a temporary reprieve. When my family and I first squeaked over this narrow neck in 1960 by jeep, furtive glances to right or left showed the two canyons perilously close, and complete severance seemed imminent. The road builders have staved off disaster for a few thousand years, but ultimately the large section to the south will become another island, and a bridge will be required to connect it to the mainland. Its appearance from the air before the road widening is shown in figure 11.

The entrance road to Island in the Sky intersects U.S. Highway 163 at a point 10 miles northwest of Moab, or 21 miles southeast of Crescent Junction on Interstate Highway 70. From U.S. 163 a paved road climbs colorful Sevenmile Canyon past sandstone cliffs of the Wingate, Kayenta, and Navajo Formations to reach the high mesa. There, just “offshore” to the north, are anchored the “battleships” that guard the island—Merrimac and Monitor Buttes (fig. 12). These landmarks are composed of the Entrada Sandstone—the same rock that forms Church Rock at the entrance to the Needles district (fig. 37) and that shapes the spectacular arches in Arches National Park. All three members of the Entrada (Wright and others, 1962), as noted in the figure 12 caption, are present here as well as at Church Rock. Eleven miles from the junction with U.S. Highway 163 a graded road to the right, called Horsethief Trail, goes 16 miles down to the Green River, where it connects with roads following the river both upstream and downstream. The road upstream leads to two uranium mines in the lower part of Mineral Canyon which were reactivated in 1972 and 1973. The switchbacks are quite spectacular and are reminiscent of the Shafer Trail. Three miles south of the Horsethief Trail turnoff is a fork in the road—to the left the pavement continues to Dead Horse Point, and straight ahead a graded road leads southward to the Island in the Sky district of Canyonlands National Park.

Most of Island in the Sky has a scattered growth of piñon and juniper trees, but several large flat areas, such as Grays Pasture, contain sufficient sandy soil to support a mantle of grass and weeds, which is used for grazing; however, grazing in this part of the park will be discontinued in 1975.

DEAD HORSE POINT STATE PARK

Let us follow the paved road from U.S. Highway 163 all the way to Dead Horse Point, which was set aside as a state park in 1957. The park has a visitor center, museum, modern campgrounds and picnic facilities, and piped water, which is hauled all the way from Moab. An entrance fee of $1 permits us to drive across the narrow neck to a parking area near the point proper, which is protected by stone walls and is provided with a ramada, benches, paths, and sanitary facilities. From Dead Horse Point we get breathtaking views in several directions, including a loop of the Colorado River called the Goose Neck, 2,000 feet nearly straight down.

How did such a magnificent viewpoint get such a macabre name? Dead Horse Point was named for a sad but colorful legend concerning a band of wild horses that once roamed the high mesas. The point is really an embryo island separated from the mainland by a narrow neck barely wide enough for the present road. In the early cowboy days the island was used as a natural corral in which wild mustangs were penned up behind a short fence across the neck so that the better ones could be sorted out and driven to mines in the San Juan Mountains of Colorado. A band of horses corralled too long without water allegedly died of thirst within sight of the river 2,000 feet below, hence the name of the point, or at least so one version of the story goes. Some versions allude to the wranglers as cowboys; others, as horsethieves.

To the northeast we can see the Cane Creek anticline—an upward fold of the rocks—behind which loom the La Sal Mountains (fig. 13). A cutaway view of a typical anticline is shown in figure 14. A better view of the Cane Creek anticline can be seen from Anticline Overlook, as shown in figure 31. From our vantage point at Dead Horse Point, we can see much of Hatch Point, including Anticline Overlook, by looking east and southeast. Spectacular views of the northern part of Canyonlands National Park lie to the south, southwest, and east. Looking southwest (fig. 15), we see most of the rock formations exposed in Canyonlands—more than can be seen from any other vantage point in or near the park. The names of the visible rock units shown in figure 15 can be compared with the complete list in the rock column (fig. 9). Parts of Shafer dome, a “closed” rounded anticline, are visible in the lower left of figure 15 and in the lower right of figure 13. Its general domelike shape is outlined by the bluish-white Shafer limestone, a marker bed which also caps the bench on the peninsula within the Goose Neck of the river. This limestone, which here forms the top of the Rico Formation, is not shown in the rock column (fig. 9) because its exposure is limited to the Shafer dome and the Cane Creek anticline and its name is used only locally by prospectors for oil and gas.

Note that the White Rim Sandstone Member of the Cutler Formation, referred to hereinafter simply as the White Rim Sandstone, becomes thinner toward the right (northeast) in figure 15 but is absent entirely in figure 13, just a short distance to the northeast. The gradual disappearance of recognizable beds of this type toward the northeast, including the disappearance of some limestone beds containing marine fossils, are examples of what geologists call facies changes. Here the changes result from the fact that while strata were being deposited in or near ancient seas that lay to the southwest, beds of different character were being laid down on land by streams emanating from the northeast. This will be gone into in more detail in discussions that accompany illustrations to follow, particularly figure 27, fig. 31, and fig. 35.

NORTH ENTRANCE

The north entrance to the Island in the Sky district of Canyonlands National Park used to be 6 miles south of the junction with the paved road to Dead Horse Point, but since the land additions of November 1971, it is only 4½ miles south of this junction. A temporary trailer-housed entrance station marks the old boundary.

SHAFER AND WHITE RIM TRAILS

During the early 1950’s a remarkable but hair-raising road known as Shafer Trail was cut down the face of the cliffs below The Neck to reach the C Group of uranium claims near the head of Lathrop Canyon. It branches southward from the park road a mile south of the new entrance, then descends in a series of switchbacks. The aerial view (fig. 11) shows the upper trail and The Neck before the park road was graded and widened, and a view from near The Neck (fig. 16) shows the precipitous cliffs the trail descends. It follows the general route of an old foot trail.

Shafer Trail connects with the White Rim Trail, which, as the name suggests, is built mainly on the White Rim, after which the White Rim Sandstone was named. The White Rim Trail can be followed northeastward to join the pavement at Potash, or it can be followed southward along the Colorado River canyons to Junction Butte, thence northward along Stillwater and Labyrinth Canyons of the Green River to and beyond the northern boundary of the park. At Horsethief Bottom, you can leave the canyon by Horsethief Trail and rejoin the paved road leading northward to U.S. 163. At Lathrop Canyon, 8 or 10 miles south of where Shafer Trail meets the White Rim Trail, a branch of the White Rim Trail leads downward to the Colorado River, where picnic tables and sanitary facilities are provided. This is used as a lunch stop by some boating groups.

Although some two-wheel-drive cars or trucks have traversed the White Rim and Shafer Trails, they may encounter trouble with deep sand, washouts, or fallen rocks, so four-wheel-drive vehicles are recommended. In the summer these trails should not be attempted without plenty of water, and two vehicles traveling together provide an added margin of safety. All vehicles should carry emergency equipment including a shovel, tow chain or rope, jack, tire tools, and other necessary items. Geologists and uranium prospectors working along the White Rim Trail have obtained good drinking water from small springs that flow from the base of the White Rim Sandstone in many places (Neal Hinrichs, U.S. Geol. Survey, oral commun., Feb. 1973). After rains, runoff gathers in large potholes in the White Rim Sandstone in some places and affords emergency drinking water. Several such potholes filled with water are shown in figure 17. Some potholes occur also in the Cedar Mesa Sandstone in the Needles district.