DOUBLE ARCH, in The Windows section. (Fig. 17)
PROBABLE STEPS IN FORMATION OF POTHOLE ARCH. A, Original pothole probably formed in relatively level bed of sandstone, such as this one, which is in an older rock unit—the White Rim Sandstone Member of the Cutler Formation, a unit not present in Arches. This pothole, which contains 4 feet of water, is in nearby Canyonlands National Park (Lohman, 1974, fig. 17), just north of the edge of the White Rim, about 4½ miles north of the confluence of the Green and Colorado Rivers. Photograph by E. N. Hinrichs. B, Pothole is being deepened by solution while cliff is receding toward pothole by weathering. C, As erosion continues, pothole and cave in cliff face are growing deeper. D, Pothole Arch formed by union of vertical pothole and horizontal cave. E, Telephoto view of Pothole Arch from park road near stop 14. Visible span is 90 feet across and 30 feet high. (Fig. 18)
The cause of the wavy bedding in the Dewey Bridge Member, as shown in figure 17 but as better shown in the frontispiece, is not known for sure but generally is regarded to be the result of irregular slumping during or just after deposition of the sediments in a body of water, caused by the weight of overlying sediments.
The last example I shall take up is Pothole Arch (fig. 18), which differs from all the other examples in that this arch is roughly horizontal rather than vertical. Most park visitors, including me, were not aware of this interesting feature until after publication of the pamphlet “The Guide to an Auto Tour of Arches National Park,” which, as previously noted, may be purchased at the Visitor Center. Pothole Arch caps a ridge high above the road half a mile northwest of Garden of Eden, so only those who happened to look up at the right place were aware of its existence.
A different mode of origin than that given in the caption for figure 18 is depicted on a poster in the Visitor Center, which shows the pothole being formed by a waterfall having an apparent flow rate of several cubic feet per second. Potholes can be formed in this manner in places where sufficient streamflow is available, either continuously or following rainstorms, but I believe the process depicted in figure 18 is a more likely mode of origin for Pothole Arch.
As aptly stated on a poster in the Visitor Center, how to see the park depends in part upon the question “How long can you stay?” Inasmuch as the park entrance and Visitor Center are beside a through U.S. Highway (163), many motorists first become aware of the park’s existence from the entrance sign, and some take time for at least a quick visit, such as a round trip to The Windows section, which can be made in an hour or so.
For those who have or take more time and are able to walk at least short distances, a visit of 1 or 2 days is a very rewarding experience. Others, particularly avid shutterbugs and those with camping gear, profitably spend from several days to a week or more and hike all or most of the trails.
Regardless of how long you plan to spend, I urge at least a brief stop at the Visitor Center, where excellent displays and a narrated slide show help materially in conveying just what the park has to offer. At the counter you can purchase a copy of “The Guide to an Auto Tour of Arches National Park,” which explains the views from each of 25 numbered stops along the park road, as well as other reports describing arches or other parks and monuments.
The park is open the year round, but, like most high deserts, it gets rather hot in the summer and cold enough in the winter for occasional snows and is sometimes closed temporarily because of heavy snowfall. The weather generally is ideal during the spring and fall. Even though summer daytime temperatures may exceed 100°F (37.8°C) and slow down hikers, the nights are cool enough for comfortable sleeping beneath ample covers.
Before beginning our trip through the park proper, let us consider a beautiful part many people fail to realize actually belongs to the park—the Colorado River canyon forming the southeastern boundary.
The southeastern boundary of the park for about 11 miles is the Colorado River, from the bridge on which U.S. Highway 163 crosses the river to a point upstream about half a mile below the mouth of Salt Wash. Illuminated night float trips down part of this reach are run during the summer, as noted on p. 16. Partly paved State Highway 128 follows the southeast side of the river for about 30 miles to Dewey Bridge, then goes northward about 15 miles to Cisco, where it connects with Highway I-70.
The rocks of the Glen Canyon Group form the southernmost corner of the park, as shown in figure 19. About 2 miles northeast of the bridge, we cross the axis of the Courthouse syncline (fig. 9), which brings the Navajo Sandstone down nearly to river level, as shown in figure 20. The underlying Kayenta Formation is largely hidden by vegetation and alluvial deposits in this view.
GLEN CANYON GROUP, forming southernmost point of park, as viewed across the Colorado River from State Highway 128 half a mile above Moab bridge carrying U.S. Highway 163. Massive sandstone forming about the lower third of cliff is the Wingate Sandstone, darker thin-bedded sandstones and mudstones forming middle section of cliff comprise the Kayenta Formation, upper cliff is the lower part of the Navajo Sandstone. Note that the saltcedar (tamarisk), which lines both banks of the river, is in full bloom. (Fig. 19)
NAVAJO SANDSTONE CLIFFS, bordering west bank of Colorado River in Courthouse syncline, from State Highway 128 about 2 miles above the Moab bridge. Note rounded domes at top of cliff. (Fig. 20)
MOUTH OF SALT WASH, viewed across Colorado River from point on State Highway 128, 11 miles above Moab bridge. Dark cliffs on upper right and left are of Wingate Sandstone capped by thin protective cover of resistant sandstone beds of the Kayenta Formation. In background Wingate is overlain by entire Kayenta Formation and lower part of the Navajo Sandstone. Wingate is underlain to river level by weathered slope of the Chinle Formation. Water in Salt Wash is largely backwater from the bankfull river; actual flow in wash generally is much less but at times reaches flood proportions. (Fig. 21)
About 11 miles above the Moab bridge is the mouth of Salt Wash (fig. 1), as viewed from State Highway 128. (See fig. 21.) Seventeen miles above the bridge (east of area shown in fig. 1), we get an excellent view of the southeast end of the highly faulted Cache Valley anticline, as shown in figure 22. The background shown in the photograph formerly was the easternmost part of the former monument, but when the monument graduated to a park on November 16, 1971, this part of Cache Valley along with most of Dry Mesa was withdrawn from the park and put under the supervision of the Bureau of Land Management, also a part of the Department of the Interior.
SOUTHEAST END OF FAULTED CACHE VALLEY ANTICLINE, viewed northwestward across Colorado River from a point on State Highway 128, 17 miles above Moab bridge. High cliff of Wingate Sandstone on left is capped by thin protective layer of the Kayenta Formation. About upper third of slope below base of cliff is the Chinle Formation, below which is the Moenkopi Formation extending to high-water level. Note bent and broken beds on right. (Fig. 22)
As noted on page 16, part of “Run, Cougar, Run” was filmed just upstream from the irrigated field in the foreground of figure 22, in a wide part of the valley called Professor Valley (fig. 7). This valley and the Richardson Amphitheater on the southeast side of the river were named after a Professor Richardson who settled in the area in the 1880’s. The long abandoned townsite of Richardson was 1¼ miles due east from the point from which figure 22 was taken.
The junction of the park road with U.S. Highway 163 is shown at the lower left of figure 23, and the entrance station, Visitor Center, parking lot, and several buildings are seen at the lower right. Several residences for park personnel and other buildings are shown in figure 25. As shown in the lower part of figure 23, the geology at the park entrance is rather complex, as the park boundary here is partly along the Moab fault and partly along a branch fault—both in the Seven Mile-Moab Valley anticline (fig. 7). The Moab fault extends northwestward from Moab for more than 30 miles (McKnight, 1940, p. 120, 121, pl. 1).
As shown in figure 23, soon after leaving the checking station the park road begins to ascend the first of several switchbacks, and cuts first into the Slick Rock Member, then the Dewey Bridge Member, and finally the Navajo Sandstone the rest of the way to and beyond the top of the hill.
From points a mile or so up the hill may be seen interesting features in several directions.[5] The view to the southwest is shown in figure 23, to the west are the Three Penguins (fig. 24). A good view of the Moab Valley is had by looking southeastward (fig. 25). A well in the Navajo Sandstone at the base of the hill supplies water to all the residences and to the Visitor Center, where a drinking fountain and modern restrooms are available to the public. Storage is provided by a steel tank hidden in a ravine above the buildings shown in figure 25.
To the north the wall of Entrada Sandstone is cut by a normal fault (fig. 6), as shown in figure 26.
FAULTED SEVEN MILE-MOAB VALLEY ANTICLINE. Top, View toward the southwest from park road about 1 mile above entrance station. Bottom, Geologic interpretation of photograph in part after McKnight (1940, pl. 1). Moab fault and branch fault (both normal faults, fig. 6) unite just beyond ridge of Slick Rock Member. Total vertical displacement along both faults is about 2,500 feet. H.F., unnamed upper member of Hermosa Formation; M.F., Moenkopi Formation; D, downthrown side of faults; U, upthrown side. Valley fill and slope wash of recent (Holocene) age obscure faults and underlying rocks. The original sequence of the rocks may be visualized by placing the Navajo Sandstone, the upper part of which is exposed at the lower right, on top of the Kayenta Formation, the lower few feet of which cap and protect the cliffs of Wingate Sandstone in the background. The Pacific Northwest (gas) Pipeline mentioned on page 15 is buried beneath the slice of the Moenkopi Formation between the two faults, which accounts for the disturbed appearance of the rock. (Fig. 23)
THREE PENGUINS, viewed westward from park road about 1 mile above entrance station. Penguins are carved in massive Slick Rock Member seen resting upon thin-bedded Dewey Bridge Member. (Fig. 24)
MOAB VALLEY, viewed southeastward from park road about 1 mile above entrance station. Moab fault in about middle of valley, hidden beneath recent (Holocene) valley fill and slope wash, separates unnamed upper member of Hermosa Formation just above U.S. Highway 163 on right from Navajo Sandstone forming hills on left and ledges in foreground. Park Service residences at base of hill. White patch bordering Colorado River on northwest is tailings pile of Atlas Corporation’s uranium mill. Moab and Spanish Valley are beyond river, and south end of La Sal Mountains forms distant skyline. (Fig. 25)
FAULTED WALL OF ENTRADA SANDSTONE, north of park road about 1 mile above entrance station. Fault is nearly vertical and normal (fig. 6), but fault trace slopes steeply downward to right, separating upthrown Slick Rock and Dewey Bridge Members on left from downthrown Slick Rock Member on right. Light-colored rock in foreground is Navajo Sandstone. Displacement probably does not exceed 50 feet. (Fig. 26)
PARK AVENUE, viewed to the north along trail. (Fig. 27)
About 2.3 miles from the entrance station is a turnoff and parking area at the south end of the Park Avenue trail (stop 2), which is about 1 mile long and ends at another parking area 1.7 miles farther north. An interesting hike is best made from south to north in a downhill direction, and hikers generally meet the cars of relatives or friends awaiting them at the northern parking area. The trail begins in a canyon cut in the soft Dewey Bridge Member and walled by high fins of the Slick Rock Member (fig. 27), but farther north the canyon is floored by the bare Navajo Sandstone. The avenue was named from the resemblance of the east wall to a row of tall buildings. Atop the west wall, just to the left of the view in figure 27, are two balanced rocks (fig. 28). The one on the left, which resembles somewhat the head of an Egyptian queen, is offset to the right along a bedding plane, and this offset may have been caused by an earthquake.
As we progress toward Courthouse Towers proper, lofty fins and monoliths lie mostly on our left, and to the right are fine distant views of the La Sal Mountains (stop 4). A general view of the Courthouse Towers is shown in figure 29, and closeups of two of the named rock sculptures—the Three Gossips and Sheep Rock—are shown in figures 30 and 31. Just beyond Sheep Rock, which some think resembles the Sphinx, we see “Baby Arch,” shown in figure 15.
Five miles from the entrance station, the road crosses Courthouse Wash on a modern bridge (stop 6)—a distinct improvement over the two tracks in the sand we used in 1946. The Courthouse syncline, named after the wash, extends northwestward through here. (See figs. 8, 9, 20.) About a mile west of the bridge, Professor Stevens found another pothole arch. A mile and a half north of the bridge is stop 7, where attention is called in the booklet to the vast area of “petrified dunes” east of the road, which are simply dunelike exposures of the crossbedded Navajo Sandstone formed originally by the cementation of a vast area of sand dunes. My view of these was taken about 1 mile beyond the stop (fig. 32).
BALANCED ROCKS ON SOUTH WALL OF PARK AVENUE, at south end of trail. (Fig. 28)
COURTHOUSE TOWERS, viewed to the northwest from point on park road about three-fourths of a mile northeast of the south end of Park Avenue trail. Sandstone towers are Slick Rock Member resting on Dewey Bridge Member, which also forms foreground. Three Gossips at upper left, Sheep Rock just beyond. The Organ and Tower of Babel are on right. (Fig. 29)
THE THREE GOSSIPS, shown at upper left of figure 29. (Fig. 30)
SHEEP ROCK, shown on center-left skyline in figure 29. (Fig. 31)
West of the road between the petrified dunes and The Windows section, the Entrada Sandstone, particularly the Dewey Bridge Member, has been weathered into grotesque spires and pinnacles resembling the so-called “hoodoos and goblins” in Goblin Valley State Park, just north of Hanksville, Utah. Typical examples of “hoodoos and goblins” are shown in figure 33 (near stop 8). It seems reasonable to assume that some of these spires are the skeletal remains of former arch abutments. From here may be seen North and South Windows and Turret Arch on the skyline to the northeast (figs. 37-40).
PETRIFIED SAND DUNES, looking northeast from park road 2.7 miles north of Courthouse Wash. The Navajo Sandstone was once a huge sandpile of dunes laid down by winds during an arid interval, so it is interesting to note that the irregularly weathered sandstone once again resembles a pile of crossbedded dunes. See also figure 35. (Fig. 32)
“HOODOOS AND GOBLINS,” weathered from Dewey Bridge Member, viewed northwest from park road about 2½ miles north of Courthouse Wash. (Fig. 33)
The Windows section, one of the most beautiful parts of the park, once was the only readily accessible part of the former monument and is still the only collection of arches seen by many visitors who either do not have or do not take time to travel farther north. All the arches and erosion forms are on or near a high crest called Elephant Butte (Dane, 1935, p. 126, 127), which separates Salt Valley from the Courthouse syncline. The ridge also marks the south edge of several minor anticlines and synclines termed by Dane the “Elephant Butte folds.”
EYE OF THE WHALE, one of several arches in Herdina Park, just south of jeep trail about 2 miles northwest of Balanced Rock. Cut in Slick Rock Member. Front opening is 60 feet wide and 27 feet high, but back opening is only 35 feet wide and 11 feet high. Photograph by Professor Dale J. Stevens, Brigham Young University. (Fig. 34)
Guarding the approach to The Windows section is Balanced Rock (stop 9). As shown in the frontispiece, it is accompanied on the right by another balanced rock and a third one may be seen in the distance. The original route to The Windows section, pioneered by Goulding, passed just north of Balanced Rock. Traces of the old road between here and the Garden of Eden parking area are still visible but no longer used. To the west, however, a part of the old road is the starting point of a jeep trail leading northwestward through Herdina Park to a point near Klondike Bluffs, where it joins the dirt road in Salt Valley (fig. 1). Visitors having four-wheel-drive vehicles may wish to drive at least as far as Eye of The Whale (fig. 34), which is about 2 miles northwest of Balanced Rock. There are several picnic tables at the beginning of this jeep trail, but no water.
INTRICATE CROSSBEDS IN NAVAJO SANDSTONE, on north side of road between Garden of Eden and Cove of Caves. Red crest is basal part of Dewey Bridge Member. (Fig. 35)
Just beyond Balanced Rock, a branch paved road turns eastward 2½ miles to the main parking lots in The Windows section. Between the Garden of Eden (stop 13) and Cove of Caves are spectacular exposures of the Navajo Sandstone showing the crossbedding typical of the original dunes (fig. 35). Just east of the crossbedded Navajo Sandstone, shown in figure 35, we pass Cove Arch and Cove of Caves (stop 10) on the north side of the road (fig. 36).
Just around the curve east of Cove of Caves is the first of two parking lots (stop 11) forming a one-way loop at the end of this branch of the road. From the loop may be seen the greatest concentration of readily accessible arches in the park, all of which are roofed by the Slick Rock Member and floored by the Dewey Bridge Member. Let us take the short paved trail from the upper lot to the southeast, where we come first to North Window (fig. 37). If we walk through this arch and climb the rock beyond (fig. 37 caption), we see one of the best views in the park (fig. 38). A short walk south of North Window brings us to South Window (fig. 39). The other side of this arch may be reached either by walking around the nearby southeast end of the fin or by walking through North Window. A short walk to the southwest brings us to Turret Arch—the one seen through North Window in figure 38. Figure 40 was taken from the southwest side of Turret Arch, viewed northeastward toward South Window, one corner of which appears at the left. Both North and South Windows may be seen in one photograph taken from points near Turret Arch.
COVE ARCH AND COVE OF CAVES, on north side of road just west of Double Arch and Parade of Elephants. Arch at left and three of the caves on right are roofed by Slick Rock Member and floored by Dewey Bridge Member. Arch is 48½ feet wide and 34 feet high. In time the caves will eat through the 30-foot-thick fin and become arches. Note sharp contact between Dewey Bridge Member and Navajo Sandstone. (Fig. 36)
NORTH WINDOW, viewed to the northeast. Large rock seemingly partly blocking left end of arch actually is the southeast end of a fin some 50 feet or more beyond the arch, from which figure 38 was taken. Arch is 93 feet wide and 51 feet high. (Fig. 37)
From the lower parking lot (stop 12), a short walk by paved trail takes us to spectacular Double Arch, shown in figure 17. This arch is visible from the parking lot but is best seen and photographed from at or near the end of the trail. Looking westward from near the trail’s end, we see the Parade of Elephants, shown in figure 41. This feature is described on pages 16 and 17 of “The Guide to an Auto Tour of Arches National Park” as “whimsical stone statuary resembling a circus pachyderm parade. With tail in trunk, the elephants rumble toward you along a sandstone roadway.”
Ribbon Arch, on the north side of Elephant Butte, is one of the most delicate ones in the park (fig. 1). Although it is 50 feet wide and 55 feet high, the rock span is only 1½ feet wide and 1 foot thick.
On the way back to the intersection with the main park road, we pass stop 14, from which may be seen Pothole Arch (fig. 18). One and one-half miles north of the intersection with the main road is the Panorama Point parking area (stop 15), which affords fine distant views of Salt and Cache Valleys and points beyond. A roadside exhibit portrays the gradual development of the Salt Valley anticline, which supplements my description on pages 27-32. A parking space a short distance farther down the hill (stop 16) provides good distant views of the Fiery Furnace. I tried several telephoto shots from this viewpoint, but preferred my closeup views, such as the one shown in figure 44.
LOOKING SOUTHWESTWARD THROUGH NORTH WINDOW, from fin shown beyond left side of North Window in figure 37. Turret Arch (fig. 40) is seen at right middle ground, south rim of Moab Valley to left of arch, Colorado River canyon forms left skyline. (Fig. 38)
SOUTH WINDOW, viewed toward northeast. Arch is 105 feet wide and 66 feet high. See text. (Fig. 39)
Two and a half miles northeast of the road intersection near Balanced Rock, a gravelled side road leads northeastward to several points of considerable interest. The photograph in figure 11 was taken from this side road about half a mile northeast of the intersection. About 2 miles to the northeast, just beyond Salt Valley Wash, is a parking area (stop 17) at the beginning of the trail past Wolfe’s Bar-DX Ranch (fig. 3) to famed Delicate Arch, which is featured on the front cover. Although the trail to the arch is only 1½ miles long, it crosses several hills at the outset, then climbs 500 feet, mostly on bare Entrada Sandstone, so is considered quite strenuous, particularly in hot weather. The Park Service advises hikers to carry water. The Walt Disney crew, cameras, gear, cougars, and all climbed this trail in the hottest part of the summer of 1971 (see p. 16), while my wife and I were working in the vicinity. Visitors who do not wish to make the hike may get a distant view of Delicate Arch by driving to a parking area (stop 18) 1.3 miles farther east.
TURRET ARCH, viewed northeast toward South Window, part of which is visible on left. Small opening on right is visible also in figure 38. Largest arch is 39 feet wide and 64 feet high; smaller one is 12 feet wide and 13 feet high. A still smaller one, not visible in the photograph, is 8 feet wide and only 4½ feet high. (Fig. 40)
PARADE OF ELEPHANTS, viewed west from end of trail to Double Arch. Two elephants are on right, one on left. (Fig. 41)
After leaving Wolfe’s Ranch, the trail to Delicate Arch crosses Salt Wash on a suspension foot bridge (fig. 42). Just beyond the bridge, a short walk to the left (north) leads to the Ute petroglyphs shown in the lower photograph of figure 2. The most difficult part of the trail, on bare sandstone, is marked by cairns of stones placed at sufficient intervals to keep hikers from losing the barely visible trail. When the summit finally is reached and the last corner rounded, one suddenly sees perhaps the most sublime view in the park—famed Delicate Arch, framing part of the La Sal Mountains beyond (fig. 43). This graceful arch and mighty Landscape Arch (fig. 53) were considered to be in serious jeopardy during the era of sonic booms, but hopefully this danger now is past. (See p. 16-17.)
It may be of interest to shutterbugs that professional photographer Hal Rumel lugged an 8- × 10-inch camera plus a heavy tripod and accessories up the steep trail to get the excellent photograph of Delicate Arch shown in figure 43. The late afternoon sun intensified the red somewhat, but my shots made earlier in the day using both 4- × 5-inch and 35-mm equipment resulted in unwanted shadows, even though the salmon color of the Slick Rock Member was more nearly normal.
After leaving the junction with the side road, the main park road traverses slices of vertical strata squeezed between faults along the north side of Salt Valley, then gradually climbs out of the valley for about 2 miles to a parking area (stop 19), from which good views are had of the southeast end of Salt Valley and of the grabens in the west end of Cache Valley. (See fig. 11.)
SUSPENSION FOOT BRIDGE ACROSS SALT WASH, in front of Wolfe’s cabin at beginning of Delicate Arch trail. (Fig. 42)
DELICATE ARCH, from end of trail 1½ miles above Wolfe’s Ranch. The opening is 33 feet wide and 45 feet high. The left abutment is only 5 feet wide at the narrowest point. The arch is carved near the top of the Slick Rock Member, and the top of the span, 19 feet thick, is capped by a few feet of the more resistant Moab Member, as is Broken Arch (fig. 16). Photograph by Hal Rumel, Salt Lake City. (Fig. 43)
About half a mile farther uphill is a parking area for viewing the southeastern part of the Fiery Furnace (stop 20), a vast array of towering fins and pinnacles of the reddish Slick Rock Member separated by narrow slots, vaguely resembling flames shooting skyward. The view of the Fiery Furnace in figure 44 was taken about 1 mile farther up the hill. It is not difficult to get lost among this myriad of fins and narrow slots, so ranger-guided tours are conducted during the summer.
About 1 mile farther northwest is a parking area (stop 23) from which a short walk to the north end of Fiery Furnace leads to a narrow slot between high fins (fig. 45), along which a short sandy trail leads to a recess along the southwest wall containing Sand Dune Arch (fig. 46). This hidden arch receives sunshine only near the middle of the day and is a delightful, shady place to rest.
From the entrance to the slot leading to Sand Dune Arch, a trail goes half a mile north across an open field to Broken Arch, shown in figure 16. This field, which separates the Fiery Furnace and Devils Garden areas, is seen from the air in figure 12.
FIERY FURNACE, viewed northwest along park road about 1 mile northwest from stop 20. Fins and spires are of the jointed Slick Rock Member (fig. 12), but the top of the Dewey Bridge Member is seen to the right of the curve in the road. (Fig. 44)
TRAIL TO SAND DUNE ARCH, looking northwest away from arch, between towering fins of Slick Rock Member, at northwest end of Fiery Furnace. Southeast end of Devils Garden in distance. (Fig. 45)
SAND DUNE ARCH, in recess along southwest wall of narrow slot shown in figure 45. Slick Rock Member. (Fig. 46)
Before proceeding to the end of the paved road, let us take an unimproved side road, which turns south about a third of a mile beyond the last stop, in order to see more of Salt Valley and to visit Klondike Bluffs in the northwestern part of the park. After descending 2.3 miles of winding road we reach the normally dry bed of Salt Valley Wash, and turn abruptly to the northwest. For the next three-fourths of a mile the “road” is simply two tracks in the loose, sandy bed of the wash, which obviously should not be travelled when flooded or when there is even a hint of rain. In dry weather, however, this road may be travelled by ordinary passenger car. This stretch of the wash cuts through an intruded block of the Paradox Member of the Hermosa Formation consisting mainly of gray and brown gypsum, the common salt having been dissolved out by ground water. Such an intrusive block of salt-bearing rock is known to geologists as a diapir—not to be confused with the garment (diaper) worn by infants.
From here on the road traverses a rather uninteresting stretch of valley north of Salt Valley Wash. Eleven miles from the starting point, the road reaches an intersection from which a side road leads southwestward three-fourths of a mile to a parking area at the foot of Klondike Bluffs, which form the south side of Salt Valley. From here, one may make a strenuous hike over a primitive trail about 1½ miles long to beautiful Tower Arch (fig. 47).
The valley road continues northwestward from the intersection to and beyond the northwest end of the park and connects with roads to Crescent Junction, Thompson, and the Yellow Cat mining district, north of the park (p. 14).
Let us return to the paved road and continue our tour of the park.
Turning left (northwest) at the intersection with the paved park road, we enter Devils Garden—another large maze of towering red fins separated by narrow slots, which resembles the Fiery Furnace. After a third of a mile, we reach stop 24 and walk 100 feet or more to the north for a good view of Skyline Arch (fig. 48). This arch is very appropriately named, as it forms the skyline viewed either from the road on the south or from the campground on the north, from points south of the amphitheater. Less well known is the fact that Skyline Arch is clearly visible to the naked eye or through binoculars from stretches of Highway I-70 (or old U.S. Highways 6 and 50) about 11 miles to the north. Most arches and other erosion forms do not change appearance much from day to day or year to year, but some, like “Baby Arch” (fig. 15), show evidence of relatively recent origin. In November 1940 (Abbey, 1971, p. 42) Skyline Arch suddenly doubled in size by the fall of a large rock that occupied what is now the northwest half of the arch. Photographs taken before and after this event appear on pages 24 and 25 of the road guide and also in the museum at the Visitor Center.