Intermountain Region

The arch is located four miles south of Parowan in section 35, T.35 S., R.9 W., on the west side of Parowan Canyon (State Road 143).

The arch can be seen from southern Parowan, and can be reached by driving up a jeep road west of the arch and scrambling up a steep mountain face. Formed in a poorly cemented section of the Grand Castle Formation (an unlikely place to find an arch because of the rock’s gravel-like composition), the arch spans about 12 feet and is about 4-1/2 feet high. (From:  Survey Notes, Utah Geological Survey, January 2001, v. 33).

Second Left-hand Canyon Arch lies four miles southeast of Hole in the Wall Arch, in section 19, T.35 S., R.8 W. on the east side of State Road 143.

One of at least four arches in the upper Claron Formation (pink limestone) along Center Creek, this rectangular arch has a span of 20 feet and a height of 13 feet, and can be seen from the road traveling down canyon, or reached by an easy hike. (From:  Survey Notes, Utah Geological Survey, January 2001, v. 33).

From Salt Lake City, UT, head south on I-15. Take the Scipio exit (188) to US Highway 50. Travel 30 miles on Highway 50 to Salina and follow the signs to merge onto I-70. I-70 passes through Salina Canyon.

A quick drive through Salina Canyon on I-70 takes the visitor on a whirlwind geologic tour. Classified as a high-altitude desert, the area of Salina Canyon was once a hot, humid coastal plain between the mountains and the sea. About 65 million years ago, near the end of the Cretaceous period when dinosaurs still thrived, water inundated the dense vegetation so quickly that decomposition could not take place resulting in the thick coal seams found today. Sea level fluctuated burying the coal bed beneath other sedimentary layers. These coal seams are very apparent, even from the road.

Since then, the Colorado Plateau experienced uplift, raising the region over a mile. Movement of the North American plate and uplift of the plateau have helped to dramatically change the climate found in Salina Canyon today (Godfrey).

From Highway 10, exit at Ferron, UT. Travel west on road 022 toward Millsite Resevoir until you come to the overlook.

This overlook provides breathtaking views of Ferron Canyon and the San Rafael Swell.

The San Rafael Swell is a large asymmetric anticline about 75 miles long and 30 miles wide. The western limb is gently inclined while the eastern limb is nearly vertical. The Swell is composed of the Moenkopi, Chinle, Wingate, Navajo, and Carmel Formations. It was likely created during the Laramide orgogeny when the North American plate and Pacific plate collided, which created compressional forces and buckling within the continent. The Waterpocket Fold in Capitol Reef National Monument to the south and the Uinta Mountains to the north also resulted from this head-on collision about 65 million years ago.

Later, erosion and uplift of the Colorado Plateau helped to create the spectacular scenery of this area.

From Highway 89 take Highway 137 to Mayfield, UT. Head west on road 022. Turn north on Skyline Drive (road 150).

The elevation at the highest point on Skyline Drive is 10,094 feet. Here you will have views of the Wasatch Plateau, adjacent mountain ranges, and Sanpete Valley.

Composed of high table land at the southern end of the Wasatch Range, the Wasatch Plateau rises to a high point of 11,300 feet at South Tent Mountain. On the southern end of the Manti-LaSal National Forest near the Fishlake National Forest border, scenic Musinia Peak rises to an altitude of 10,986 feet. The average altitude of the plateau is roughly 11,000 feet. It towers a vertical mile over Sanpete Valley on the west and Castle Valley on the east. The summit is a long narrow platform that never reaches more than 6 miles in width. To the east, the land drops off dramatically through a series of striking white, pink, pale orange and buff-colored cliffs. The lower terraces and benches, at intervals of about three to six miles, reveal older and older strata as they descend. Geologically complex and fascinating, the Wasatch Plateau contains Cretaceous, Laramie, Tertiary, and Jurassic formations.

From Monticello, UT, west off Highway 191, travel on road 104 towards Monticello Lake. Overlook is located about 1.5 miles past lake.

Scenic overlook of Needles District of Canyonlands National Park.

(1) A large sandstone arch is visible from the junction of Peavine Canyon and Dark Canyon. Begin 25 miles west of Blanding, UT near the junction of Highway 95 and 275. Take Forest Road 088. The overlook is about nine miles after the junction from 275 and passes between the Bears Ear Formation. When the road forks, do not take road 092, but stay on 088 heading north towards Hammond Canyon Overlook. 4WD is needed to continue on road 089 about 8 miles up Peavine Canyon.

(2) A large sandstone arch is visible in a cliff dweller’s pasture. Travel north from Blanding, UT on the highway towards the National Forest boundary. The road will turn to gravel. Travel on road 095 about 11 miles and the arch is located to the west.

The development of classic arch formations occur when parallel fractures in brittle rocks are exposed and favorable predisposing factors such as soft bedding-planes, indentations, and thin, soft rock layers occur. In Utah, especially near and in the regions of Arches National Park, salt anticlines have rolled the rocks over, turning bedding planes vertical, exposing them to rapid rates of erosion. The parallel joints erode vertically creating fins (see figure 1 below). Loose sands will accumulate between the fins and hold slightly acidic rainwater, through capillary action and surface tension, to the slightly calcareous sandstone walls. With enough persistence, a horizontal crevice will begin to erode. As the crevice enlarge, the weight on the limbs of the forming arch increases due to gravity of the overlying rocks. This stress creates fractured blocks that form from the arch until the characteristic arch forms. This process is known as upward stopping". The size of the arch is dependent on the thickness of the sandstone fins or walls (Doelling, 2003). 

Pothole arches form differently than the classic arch explained above. Run-off on tops of the cliffs and buttes will swirl and erode the surface until a drilled hole is near the cliff face. The running water will continue to erode downward carving an alcove at the base of the cliff. The joining of an alcove and pothole creates a pothole arch. (Doelling, 2003). 

Begin 25 miles west of Blanding, UT near the junction of Highways 95 and 275. Take Forest Road 088. When road forks, continue north on road 088 about 7 miles to overlook.

Views of Dark Canyon Wilderness to west and Notch Canyon to east.

Begin 25 miles west of Blanding, UT near the junction of Highways 95 and 275. Take Forest Road 088. Bear Ears is about six miles after the junction from 275 and the pass is between the two formations of Bears Ears. (This route is considered the Elk Ridge Road Scenic Backway, which extends across the Blue Mountains through the high desert and ends at Highway 211. The backway is approximately 50 miles long and about four hours driving time.)

Bears Ears is a unique geologic formation visible for miles in all directions and composed primarily of Wingate Sandstone. As a member of the Glen Canyon Group, it consists of well-rounded, fine-grained, quartzose sandstone and its iron-oxide cement helps to produce its characteristic pink-orange color. This sandstone was deposited in ancient coastal sand dune environments. The sand dunes covered most of the Colorado Plateau about 220 to 200 million years ago. You might recognize this same formation and its massive cliffs exposed throughout Canyonlands and Capitol Reef National Parks.

Begin 25 miles west of Blanding, UT near the junction of Highways 95 and 275. Take Forest Road 088. When road forks, continue north on road 088 about 1.5 miles to overlook.

Overlooks a deep sandstone canyon of sculpted pinnacles.

Grouse peak is a piece of the crater rim that has not moved much (14 miles northeast of Challis in Lost River Range). The slope behind Challis Hot Spring is a conglomerate breccia that is part of the ejecta blanket. Look for shatter cones in Belt and Lemhi rocks.

The Beaverhead Impact Structure is one of only eight known bolide impacts with craters over 50 km in diameter. Scientists now believe that the center of the Beaverhead Impact Crater is in Idaho within the Salmon-Challis National Forest.  It is 60 km in diameter and the impact is estimated to have occurred about 900 million years ago.  Tectonism has broken up regions of the original shocked rocks and dispersed them as large discrete areas across the geological landscape.  Direct evidence for the structure is found at Island Butte in the southern Beaverhead Mountains, Montana where shatter cones and shocked grains are found in Mesoproterozoic sandstone, and the underlying Archean gneiss contains pseudotachylite dikes and pods (injection breccias emplaced in fractures during meteoric impact). (see Carr and Link, 1999)

The trailhead is located near the Bighorn Crags campground. From Challis, drive 9 miles north on Highway 93 to the Morgan Creek Road turnoff. (on the left) Follow this pavement/gravel road for 20 miles to the Morgan Creek Summit where it becomes the Panther Creek Road. Follow this road another 14 miles to the signed turn-off at Porphyry Creek. Follow the Porphyry Creek Road 6 miles to a four way intersection. Turn right at this intersection on Forest Road 114. There will be another intersection with the road to Yellowjacket Lake. Bear right continuing on road 114 past the Crags campground to the trailhead.

Most prominent in the Salmon River Range are the Bighorn Crags, located in the Frank Church River of No Return Wilderness. The Bighorn Crags feature the most spectacular peaks and lakes in the wilderness. The scenery includes craggy granite spires, high peaks, and dozens of gorgeous alpine lakes tucked into glacial cirques. The Bighorn Crags are Eocene granitic rocks intruded into Eocene volcanic rocks of the Challis volcanic group.

The best access to the National Forest portion is through Castle Rocks State Park. This is a fairly new state park was designated in 2003. From I-84 in Idaho, take the Sublett Road exit toward Malta. Turn left onto Sublett Road. Sublett Road becomes Jane Lane. Travel to 4th Street, turn left on to Main Street. Turn right onto Center Street. Turn left on Elba-Almo Road, then west 1.4 miles on 2800 S. (Big Cove Ranch Road)

The Almo Pluton hosts the spectacular granitic rock formations in City of Rocks National Reserve, Castle Rocks State Park, and the southern end of the Albion Mountain Division of the Sawtooth National Forest. Much of the geologic story resulted from moving plates and colliding continents pushing intrusive magma to the surface where it solidified. Older rocks are around 2.5 billion years old--part of the Archean Green Creek Complex--some of the oldest in the country, but none is visible within the park boundaries. Sea deposited, fused and cemented sandstones, from around 700 million years ago, make up the Elba Quartzite, which can be seen in small outcrops around the area.

The Almo Pluton, a granitic intrusion that formed around 27 million years ago, pushed its way up through overlying rocks and sediments, makes up most of the granite of the Castle Rocks area. Effective weathering and erosion in joints of the granite created the fairy-tale resistant formations that remain today.

The brown varnish, also known as desert varnish, is iron oxide leached from the water that stains the surface of the rock and creates a erosion protective layer. In places where the desert varnish has broken or chipped away, small hollows quickly weather out.

1. From the I-15/U.S. Highway 89 interchange in Farmington, head north on U.S. Highway 89 for 10.7 miles to a sign indicating the route to Morgan and Evanston. Turn right (east) on I-84 and travel approximately 23 miles to the scenic viewpoint turnoff located after milepost 110.

2. From the southern I-15/I-80 interchange in Salt Lake City; head 11.3 miles east on I-80 to exit 134 (Mountain Dell Recreation exit). Travel north on Utah State Highway 65 for 27.7 miles to the town of Henefer. Turn left (west) and proceed 1 mile to I-84. Turn left (west) onto I-84 and travel 2 miles to the scenic viewpoint turnoff located just after milepost 111.

Devils Slide is a classic example of how different rock layers, depending on their composition, are affected by weathering and erosion. The sides of the slide are hard, weather-resistant limestone layers about 40 feet high, 25 feet apart, and several hundred feet in length. In between these two hard layers is a shaley limestone that is slightly different in composition from the outer limestone layers. This middle layer is softer, which makes it more susceptible to weathering and erosion, thus forming the chute of the slide.

Looking like a large playground slide fit only for the Devil, this site is a tilted remnant of sediments deposited in a sea that occupied Utah’s distant geologic past. Approximately 170 to 180 million years ago, a shallow sea originating from the north spread south and east over areas of what are now Montana, Wyoming, and Utah. This sea extended as far east as the present-day Colorado River and south into northern Arizona.

Over millions of years, massive amounts of sediment accumulated and eventually formed layers of limestone and sandstone. In northern Utah, these rocks are known as the Twin Creek Formation and are approximately 2700 feet thick. About 75 million years ago, folding and faulting during a mountain- building episode tilted the Twin Creek rock layers to a near-vertical position. Subsequent erosion has exposed the near-vertical rock layers and created Devils Slide. 

From:  Survey Notes, Utah geological Survey, v. 35, April 2003.