Arches National Park Scenic Loop
0.0 Road Junction Arches National Park Headquarters. Turn North (Right) Off U.S. Highway 191 into the headquarters area. Rounded rocks immediately behind the residence areas are in the Navajo Sandstone. Stop and pay one dollar fee at the entrance booth near the Visitors Center.
0.4 Visitors Center. View of the Moab Valley Fault with Entrada Sandstone faulted against Hermosa-Cutler Rico Formations to the south.
0.7 Base of the Carmel formation and Top of the Navajo Sandstone. Navajo beds are exposed in vertical cuts on both sides of the road. The crinkly character of the Carmel beds shows well on the skyline.
1.6 Pull Out at Lookout Point 2. To the west, back down the road, switchbacks can be seen carved in the Navajo Sandstone and the basal beds of the crinkly Carmel Formation from the Visitors Center to the southwest to here. Massive Entrada Sandstone forms the cliffs to the north and west of the road. White cross-bedded Navajo Sandstone forms exposures below. The nonresistant crinkly beds which weather into reddish slopes are the Carmel Formation. The abrupt termination of the Entrada Sandstone against the Rico-Hermosa sequence can be seen just at the narrows in Moab Canyon beyond the Visitors Center to the southwest or just south of the first bend of the National park road beyond the Visitors Center. This expression is of the West Spanish Valley or Moab Valley Fault which here has dropped the Entrada Sandstone and underlying rocks down 2 to 3 thousand feet with reference to those formations exposed to the south of the fault.
Brick red, rounded arkosic sandstone of Cutler Formation is seen beyond the narrows in Moab Canyon where the Hermosa rocks are exposed just south of where U.S. Highway 163 disappears up Moab Canyon. Cutler rocks are overlain at about midslope by a thin sequence of Moenkopi Formation, and it in turn by the gray slope and ledges of the Chinle Formation. Angular jointed Wingate Sandstone forms the vertical cliff and skyline but is capped here and there by thin, flaggy remnants of Kayenta Sandstone. Recent sand dunes can be seen between the highway and railroad track to the south and just beyond the railroad tracks in the vicinity of the trace of the Moab Valley Fault. Ragged outcrops between the highway and the railroad to the south are Entrada beds badly broken along the Moab Valley Fault. Trace of the fault is approximately along the railroad track.
A small fault can be seen to the northwest of this stop, where the Carmel Formation abruptly terminates against massive beds of the Entrada Sandstone. Displacement of this small fault here is approximately 50 or 60 feet. This small fault is well exposed at the east end of the road cut east of this stop. Slickensides, grooved shiny surfaces, are exposed in the cut and along the fault to the east and west.
Outcrops of Carmel Formation can be seen to the north beneath the Entrada behind the Navajo Sandstone beds exposed in the immediate road cut. Sandstone Peaks of the La Sal Mountains can be seen to the east through the road cut in the Navajo Sandstone. Continue ahead into the National Park Area. The east end of the road cut is in the Carmel Formation which is now exposed as red "stone babies" to the north of the road. The road continues in the uppermost beds of the Navajo Sandstone patterned into characteristically rounded, eroded remnants.
2.6 Geologic Stop. Pull to the North (Left) into the Parking Area. Turnout 4. Entrance to the south end of Wall Street (fig. 6.22). Walk a short distance to the overlook into the joint-controlled, fin-bounded canyon. Early visitors imagined the skyline resembled that of a city. Return to the cars and turn left (east) onto main Monument road.
3.7 View east down the road toward the La Sal Mountains. Excellent exposures of Navajo Sandstone show the broad synclinal character of the Courthouse Wash structure.
4.2 Turn Around / La Sal Mountain Overlook. Courthouse Towers can be seen to the west (fig. 6.23), including the Three Gossips (fig. 6.24), Tower of Babel, and Organ Rock. To the cast, this view shows the characteristic broad down buckled syncline development of the Navajo Sandstone. Turn around and return to the main Monument highway. The main park road continues through road cuts in the Carmel Formation and uppermost beds of the Navajo Sandstone and descends down the north dipping top of the Navajo Sandstone into Courthouse Wash Syncline.
Figure 6.22. Northward along Wall Street from the parking arm. Massive sandstone cliffs are in the Moab Tongue of the Entrada Formation above the crinkly, moderately well-bedded, Dewey Bridge Member of the formation.
Figure 6.23. Aerial view southeastward to the park entrance area and Moab Valley from the northwest. The highway into the interior of Arches National Park winds through the buttes and mesas in the middle distance. Colorado River leaves Moab or Spanish Valley through the V-shaped notch in the center distance. Prominent joints in the foreground are in the upper part of the Moab Tongue of the Entrada Formation.
Figure 6.24. The Three Gossips as seen from the park road at approximately Mile 4.5. These monoliths are in the Moab Tongue of the Entrada Formation.
6.4 Cross Courthouse Wash. The wash is entrenched here into the Navajo Sandstone as well as in a thick, vertical-walled alluvial cover.
7.1 The road passes near a small isolated pinnacle of crinkly-bedded Carmel Formation. To the east the hummocky "beehive" surface of the Navajo Sandstone shows well rising on the north flank of the Courthouse Wash Syncline. The road continues ahead on the top of the Navajo Sandstone,
7.9 Turnout Point 11. Petrified dunes viewpoint. Cross-bedded Jurassic Navajo Sandstone shows in the ancient exhumed dune fields to the cast. Jointed Entrada Sandstone can be seen to the northeast in the windows section of the park.
9.5 Massive white sandstones of the basal Entrada Formation in the pinnacle area appear to have been channel sands and maybe have differentially loaded the soft underlying sediments and produced some of the crinkly character of the Entrada. At least two irregular deep penetrations of the channel sandstones down into the lower beds can be seen. Continue ahead with outcrops of basal beds of the Entrada Formation on both sides.
10.5 Turn Out at Balanced Rock (fig. 6.25). Ham Rock is perched high on the Entrada Sandstone outlier the east. The road continues ahead on the stripped surface of Navajo Sandstone or in basal beds of the Entrada Formation. Designations of the Entrada, Carmel, and Navajo Formations are shown at the east end of the pull out.
Figure 6.25. Ham Rock, a balanced-rock outlier of the lower part of the Moab Sandstone Tongue, is perched on crinkly Dewey Bridge beds of the Entrada Formation as seen from Mile 10.5.
11.2 Junction of Road to Double Arch and Windows Section of the Park to the East. Turn Right To the northeast, just beyond the road junction can be seen the south flank of Salt Valley Anticline with Wingate Sandstone beds dipping to the southeast. The road continues to the east of the junction through cross-bedded Navajo Sandstone.
11.5 Turnout Point 22. Strongly-jointed Entrada Sandstone can be seen to the north beyond Salt Valley, beneath the white cap of less intensely-jointed Curtis Sandstone.
12.4 Garden of Eden Viewpoint to the east. "Elephants" are in the Moab and Dewey Bridge Members. Cross-bedded Navajo Sandstone forms the pedestals at their base.
13.5 Beginning of one-way road. Turn around at the Double Arch and Window Arches. Turnout 18. Trails to Turret Arch and North and South Window Arches to the east. A maintained trail leads southeast from the parking lot into the arch area. One can see Turret Arch to the southwest from the trail. A small keyhole arch occurs in basal beds of the Entrada Sandstone. South Window Arch is a high round arch in basal beds of the Moab Sandstone with the Dewey Bridge beds depressed below it in a rather characteristic crinkly pattern. Some of the basal beds of the Entrada Formation may be part of the crinkled lower beds of the shear, cliff-forming Entrada. A short trail leads from the main trail to North Window Arch. An excellent view of the valley to the east can be seen through North Window Arch.
14.0 Parking zone, Turnout Point 19. A trail leads past alcoves to Double Arches (fig. 6.26) to the northwest of the parking lot. Return to the Junction with the Main Road Near Balanced Rock at Mile 11.2.
11.2 Junction of the Windows Section Road with the Main Monument Road into the Devil's Garden and Delicate Arch Sections. Turn Right (north) through cuts in the Navajo and Kayenta Formations.
Figure 6.26. Double Arches as seen from the southeast from near the end of the trail that leads from the parking area at Mile 13.5. The arches, like many other features in the park, are in massive Moab Sandstone Tongue of the Entrada Formation.
12.5 Panorama Viewpoint, turn off to cast (right). To the northwest we can see the downfaulted valley block with Jurassic and Cretaceous rocks dropped within the Salt Valley graben. The high pinnacled fin development is in the Entrada Formation, The Entrada beds are overlain by the white Curtis Sandstone and it is overlain by various colored shales of the Morrison Formation. Some gray and yellow brown weathering Mancos Shale can be seen in the valley to the north.
13.9 Gravel turn out to the cast. Gray and yellow gray hills down the valley to the east beyond the dune-covered brush area to the north are in the Mancos Shale, north of the main Salt Valley Fault. To the east the prominent high cliff is in the Wingate Sandstone which is underlain by the reddish slope of the Chinle Formation. Both the Wingate and Chinle exposures are south of the Salt Valley Fault.
14.5 Dakota Sandstone and Morrison Formation exposed to the north of the road, across the gully. These formations are the ashy-appearing beds south of the prominent sandstone in the core of the Salt Valley Anticline. Prominent white Curtis Sandstone cliffs to the north cap the top of the pink massive Entrada Sandstone, the sandstone in which most of the arches and the fins of the park have been carved.
15.8 Turn out on the north (right). View of pinnacles of Entrada Sandstone beneath the massive, light-colored, Curtis Sandstone. Colored Morrison, and gray Dakota and Mancos beds are exposed in the foreground and in the gully. Mancos beds are exposed in the bottom of the gully. Entrada beds form the castlellate surfaces along the skyline.
16.5 Salt Valley Overlook, Turn to the Right (East) on to Short Road. Beds near the anticlinal structure show very well, with formations from the Entrada Sandstone to the Mancos Shale dipping steeply to the south, off the south flank of Salt Valley Anticline. A fault, visible east of the parking area, repeats the white Curtis Sandstone. Salt Valley to the southeast is carved in the Morrison and Mancos Formations. To the south the low escarpment on the south side of Salt Valley is in Chinle Shale and Wingate Sandstone, but the latter does not form the characteristic bold escarpment here, like it does to the east apparently because of faulting and breaking of the beds.
16.8 Turn Off to the Right to the Fiery Furnace Parking Area. The La Sal Mountains rise to the cast above the folded Mesozoic rocks in the Salt Valley Anticline structures. Ahead and to the north the castellate Entrada forms the fins and stone babies in the immediate vicinity. The finned Fiery Furnace area is relatively complex topographically. It is a primitive area and the possibility of becoming lost is great. As a consequence only ranger-conducted tours are led into the Fiery Furnace area. Fins are in parallel jointed Moab Sandstone of the Entrada Formation,
17.1 View to the south shows the dip of the faulted sequence of Carmel, Entrada, Morrison, Summerville, and Mancos Formations all down-faulted against the Chinle beds which form the escarpment to the south. Navajo Sandstone is exposed in the gullies immediately south of the road. The Dewey Bridge forms the crinkly-bedded zone at the base of the Entrada cliff to the north.
17.7 Upper Fiery Furnace Turn Out. The thin finlike character of the resistant Entrada Sandstone shows well above the crinkly Dewey Bridge beds. Road cuts to the west are in the Dewey Bridge with Navajo Sandstone exposed in gullies to the south.
18.8 Viewpoint and parking area to the north (right). Maintained traits lead to Sand Dune Arch and Broken Arch to the north. Broken Arch can be seen directly to the north, at the end of a fin of Entrada Sandstone, beyond the grassy sagebrush-covered flat. Sand Dune Arch is in the same general vicinity.
19.5 Skyline Arch Turn Out. The road continues in upper beds of the Navajo Sandstone with crinkly Dewey Bridge beds exposed just above, beneath the walled cliffs of the Entrada Formation.
20.1 Beginning of One-Way Loop at the Entrance to Devil's Garden. Fins of Entrada Sandstone are well developed in areas to the east. Walk-in Picnic Area. Junipers and pinion form shady nooks in the sand-covered valleys between fins of Entrada Sandstone.
20.2 unction of Road to Devil's Garden Campground. Turn right for campground, rest room and drinking water facilities.
20.8 Parking Area at the Entrance to the Devil's Garden Trail to the west through Fin Canyon. Fins in the vicinity of the parking area are all in the Entrada Formation (fig. 6.27). Trails lead to Landscape Arch (fig. 6.29) and other arches to the west. Return on the main road toward the headquarters.
26.9 Junction Road to Delicate Arch. Turn Left, Gray Morrison beds are exposed across the canyon to the north. The road cuts through the lower part of the Mancos Shale and descends to Salt Valley Wash, primarily in the Mancos Shale. Upper beds of the Dakota Sandstone and the Morrison Formation are exposed to the north.
Figure 6.27. Joint separated fins of massive sandstone of the Entrada Formation as seen westward towards the Fin Canyon Trail area in the Devil's Garden. The Fin Canyon Trail leads through the pass between the fins to the left of the center in the photograph.
Figure 6.28. Landscape Arch is the longest and highest arch in the national park. The arch is reached by a trail westward from the Devil's Garden area through Fin Canyon.
27.4 View to the southeast of the Wingate Cliff above the Chinle and Moenkopi slopes, south of the Salt Valley Fault. The road continues in the Mancos Shale. A brown-weathering sandstone in the Dakota Sandstone forms the resistant cuesta to the north and northeast.
28.0 Cross Salt Valley Wash.
28.2 Delicate Arch Trail Parking Area to North. Turnbow Cabin, one of the early pioneer cabins, can be seen to the north, by the old pole corral. The steep southward dip here in the maroon shales and white sandstones of the Morrison Formation is typical of the south side of the Salt Valley Anticline. The pink "slick rock" rim to the north is formed of southward dipping Entrada Sandstone, Prominent high pinnacles to the east are in the Entrada Sandstone and surround Delicate Arch which is the narrow fin about in the middle of the promontories in the skyline.
28.3 Cross Culverts on Salt Wash.
28.6 Road is on gray Mancos Shale, tan Dakota Sandstone forms the first prominent hogback to the north (left) above the white and brown ledgey-appearing beds of the Morrison and Cedar Mountain Formations which form the high cuestas on the skyline to the north. To the south, across Salt Valley, Mancos Shale is faulted against basal beds of the Chinle and Moenkopi Formations. The red rocks occur on the south side of the Salt Valley Fault.
28.9 Cross the Dakota hogback. The road continues on basal beds of the Mancos Shale, along the base of the striking hogback in the Dakota Sandstone.
29.1 Cross back through the Dakota hogback onto soft gray green shales of the Cedar Mountain Formation and then through a white sandstone in the Morrison Formation. This sandstone forms the crest of the high hogback to the west. The road continues in the Morrison Formation through the narrow part of the canyon and then swings back to the southwest in a subsequent valley in the Morrison Formation.
29.3 Delicate Arch Viewpoint. Delicate Arch is in the Entrada Sandstone in the pinacles to the north. Ragged cherty beds of the Morrison are exposed immediately north of the parking area with "slick rock" of the Entrada Formation exposed below it and on to the north. Summerville beds are the deep brick red beds on top of the slick rock zone, beneath the cherty units of the basal conglomerate of the Morrison Formation. To the east, beyond the parking area, the down faulted graben shows very well, with Wingate cliffs on the north and Chinle and Wingate cliffs on the south side, with downdropped Jurassic rocks in the center of the structure. Tilted beds in the immediate foreground are in the Morrison Formation. Return to Visitors Center and to U.S. Highway 163.
from Field Guide: Northern Colorado Plateau by J. Keith Rigby - Purchase Information