THE NEEDLES AND THE GRABENS

THE NEEDLES, looking southwest from Squaw Flat. (Fig. 49)

The northeastern edge of The Needles proper can be seen from Squaw Flat ([fig. 49]), but the true character of The Needles can be appreciated better from the air ([fig. 50]). You cannot get far into The Needles without traversing part of The Grabens, so we will consider them together. An aerial oblique view ([fig. 51]) shows The Needles in the foreground and The Grabens in the middle background. As shown on the map ([fig. 1]), you can hike into The Needles and The Grabens from Squaw Flat, but let us make the trip using a four-wheel-drive vehicle and several short hikes.

THE NEEDLES AND THE GRABENS, aerial oblique view looking west over Chesler Park in foreground, The Grabens to the right, and Cataract Canyon behind. Photograph by U.S. Army Air Force. (Fig. 51)

Ordinary passenger cars now can go 2¾ miles west of Squaw Flat to Soda Spring, at the east base of Elephant Hill, but beyond Soda Spring four-wheel-drive vehicles should be used. Some people conquer the hill in dune buggies or on motorcycles, but this is considered quite dangerous. Both sides of this short (1¼ miles) but formidable hill have switchback curves too sharp to negotiate in the regular manner, so special driving techniques must be followed. On the east side, you must drive out on a flat rock, jockey back and forth until turned completely around, then proceed up the hill. On the west side, you descend a 40-percent grade to a shelf, back down a narrow stretch of about 30-percent grade and back sharply to the left onto a flat rock, then go forward again. On the return trip the whole procedure is carried out in reverse order.

West of Elephant Hill, the road reaches a Y, at which you must turn left on a one-way road; the right-hand road is for later one-way return to the Y. Why the left-hand fork is one way soon becomes apparent, for the road leads into a narrow shallow graben, called Devils Pocket ([fig. 51]), between rock walls, and is barely wide enough for one car. After about 2 miles the graben widens out into a beautiful spot called the Devils Kitchen, which contains several picnic tables tucked into shady recesses in the sandstone walls. This is the starting point for two trails leading southward by different routes to Chesler Park, from which other trails lead to Druid Arch or back to Squaw Flat.

From the Devils Kitchen, the road turns abruptly westward for about half a mile to another Y in about the middle of Devils Lane, one of the larger grabens and one of two whose entire length is traversed by roads, as shown on the map ([fig. 1]). Only the left fork is a two-way road, so let us take the left fork 2¾ miles southwestward to the next road junction. About halfway down Devils Lane, a fault crossing the graben has created a narrow steep ridge appropriately called SOB Hill, because the road over it creates a challenge that some vehicles fail to meet on the first attempt!

The next road intersection is now shown on the map ([fig. 1]) as a sharp turn leading southwest to Ruin Park and Beef Basin. The abandoned left fork (not shown) leads east into Chesler Park. This park, shown in [figure 50] and near the bottom of [figure 51], is a beautiful natural meadow of several hundred acres fenced by a natural wall of needles and containing a central island of needles. Because of vehicular damage to meadow vegetation, the National Park Service found it necessary to close the road. To reach Chesler Park now, vehicles must go right a short distance to the Chesler Canyon turnoff, then left about half a mile to a parking area. From here, a ½-mile hike east through the narrow Joint Trail gets us to the south side of Chesler Park, where we join the abandoned road to reach the northeast corner of the park and the trails into The Needles proper ([fig. 1]).

This change adds 1¾ miles (one way) to the hike to Druid Arch, making the round trip about 11½ miles. At the old trailhead, near the northeast corner of Chesler Park, is a sign proclaiming the need for rubber-soled shoes and water, and I strongly support these admonitions, for much of the hike is on bare smooth sandstone and includes steep slopes and generally dry waterfalls. The hike should not be attempted by anyone not in good physical condition, and it should not be undertaken alone; two or more people should travel together.

As shown in [figure 52], the trail to Druid Arch from Chesler Park starts out on bare Cedar Mesa Sandstone marked by a succession of rock cairns, two of which are visible and without which the trail would soon be lost. The trail drops rapidly down into Elephant Canyon, which is then followed southward 2 miles to the arch. This canyon has cut through the Cedar Mesa into the underlying Rico Formation, and much of the canyon is quite narrow and steep sided, as shown in [figure 53]. Although much of the Rico consists of red beds laid down above sea level by ancient streams, the trail crosses several thin beds of dark-gray hard limestone containing fossil marine seashells and ancient sea anemones whose original calcium carbonate parts have been locally replaced by jasper (red iron-bearing silica). When at last the weary hiker makes the steep climb out of the canyon and rounds the final bare-rock curve, the sudden and striking view of Druid Arch ([fig. 54]) seems worth every bit of the effort—at least it was to me and my hiking companion.

After my friend and I hiked to Druid Arch and after the length of this route was increased to a round-trip distance of 11½ miles, a new route was constructed having a round-trip length of only 8½ miles. This new trail starts at the end of the passenger-car road at the east edge of Elephant Hill, goes 1¼ miles southwest to join an older trail in Elephant Canyon, then follows this canyon 3 miles south to the arch.

TRAIL TO DRUID ARCH, near its beginning at northeast corner of Chesler Park, marked only by rock cairns, two of which are visible. (Fig. 52)

UPPER ELEPHANT CANYON, containing trail to Druid Arch. (Fig. 53)

DRUID ARCH, from end of arduous trail shown in figures [52] and [53]. (Fig. 54)

After returning to our vehicle west of Chesler Park and backtracking over SOB Hill to the intersection in the middle of Devils Lane, let us proceed northward on a one-way road to and beyond the Silver Stairs for a closer look at Devils Lane and other grabens to the west and for a look at the confluence of the Green and Colorado Rivers. But first let us pause and reflect upon the possible origin of The Grabens.

Geologists have different opinions as to just how grabens and complex systems of joints have formed, but all seem to agree that tensional forces were involved. Some think that solution of salt and gypsum from the Paradox Member of the Hermosa Formation by ground-water movement allowed the brittle Cedar Mesa Sandstone and other overlying rocks to sag, producing tension cracks and faults. Others believe that removal of the salt and gypsum occurred by plastic flowage toward the Meander anticline (see [p. 108] and [fig. 61]), whose axis follows the Colorado River southwest from The Loop, past the confluence, and to and beyond Spanish Bottom. Some suppose that compaction due to the weight of the abnormally thick pile of sedimentary rock underlying the area may have caused the sagging, cracking, and faulting. The rock deformation may have resulted from a combination of these and possibly other things, of course, but whatever the cause, the resulting features are very striking. There was room to show only two of the named grabens within the park on the map ([fig. 1]), but all are shown in [figure 51], and several appear in [figure 59]. A diagramatic cross section of a typical graben is shown in [figure 55]. The tension faults shown in figures [55] and [56] are called normal faults, in contrast to faults formed by horizontal compression, which are called reverse faults (figs. [75], [76]).

The Grabens range in width from about 7 or 8 feet at the north end of Devils Pocket to nearly 2,000 feet at the south end of Red Lake Canyon, but the average width is about 500 feet. The floors of The Grabens are covered by soil and grass, but the displacement along the faults is believed to approximate the height of the walls—nearly 300 feet. That The Grabens are of fairly recent origin is attested by the fact that most of the walls are vertical fault faces showing little sign of erosion ([fig. 57]); that no through drainage has yet been established in Cyclone Canyon, which is a series of basins with low divides between; and that several pre-existing streams were interrupted or diverted by the faulting.

A SIMPLE GRABEN, formed by tension in directions indicated by horizontal arrows. Downdropped central block is the graben; stationary or uplifted blocks on sides are called horsts. From Hansen (1969, p. 123). See also [figure 76]. (Fig. 55)

CUTAWAY VIEW OF NORMAL FAULT, resulting from tension in and lengthening of the earth’s crust. Note amount of displacement and repetition of strata. Compare with [figure 76]. From Hansen (1969, p. 116). (Fig. 56)

Now let us continue our journey northward along Devils Lane. Just before reaching the Silver Stairs we may wish to pause long enough to take in the distant view to the northwest toward Junction Butte and Grand View Point. (See [frontispiece].) After descending the steep Silver Stairs in a narrow cleft between rock walls, we reach another intersection: a two-way road continuing northwest goes to our destination, and a one-way road turning right returns to Elephant Hill via part of Elephant Canyon ([fig. 58]).

About 2 miles to the northwest we cross the north end of Cyclone Canyon, the largest graben. It contains a road 3½ miles long and is well worth seeing. About one-half mile from the south end, an old trail follows Red Lake and Lower Red Lake Canyons to the Colorado River across from Spanish Bottom (figs. [1], [61]).

From near the north end of Cyclone Canyon (figs. [1], [59]), we drive west three-fourths mile to a parking area and hike one-half mile to an overlook for a spectacular view of the confluence of the Green and Colorado Rivers (figs. [59], [60]) and of the northern part of Cataract Canyon ([fig. 61]). These and other canyons are discussed in the next chapter.

WEST WALL OF CYCLONE CANYON GRABEN, a nearly vertical fault face showing little sign of erosion. (Fig. 57)

LOWER ELEPHANT CANYON, followed by jeep trail from near Silver Stairs to Elephant Hill. (Fig. 58)

THE CONFLUENCE FROM THE AIR, and some of The Grabens. See also [figure 51]. Vertical aerial photograph by U.S. Geological Survey. (Fig. 59)

THE CONFLUENCE FROM CONFLUENCE OVERLOOK, shown in figures [1] and [59]. Green River entering from left, Colorado River from right. Red beds near top are Rico Formation, overlain by Cedar Mesa Sandstone and underlain by unnamed upper member of Hermosa Formation. (Fig. 60)

CATARACT CANYON, from the rim, looking south to Spanish Bottom at bend. Beds dip to left and right away from Colorado River, which here is followed by axis of Meander anticline. (See [p. 108]). Cliff below overhanging rock resembles profile of a man; the rock resembles his hat. Photograph by Walter Meayers Edwards, © 1971 National Geographic Society. (Fig. 61)