Herds of wild horses and burros roam the plains, and bighorn sheep may sometimes be spotted in the canyons. Most of the tracks across the swell result from prospectors in the early to mid twentieth century, and these provided the only access until 1972, when the interstate was constructed, dividing the region in two. Various exits now allow easy entrance to the middle section and link with the old tracks, most of which are good for regular vehicles and quite well signposted. Hiking and exploring are the main reasons to visit nowadays - there are trails to mountains, historic sites, old mines and the numerous canyons - these offer experiences ranging from extended, strenuous trips like the hike through the Black Boxes of the San Rafael River to easy walks such as that down Little Wild Horse Canyon.

Click Here for more information about the Slot Canyons of the San Rafael Swell.

Some of the many Petroglyphs

The San Rafael Swell is a 900-square mile, wild and beautiful region west of the Green River. The Swell is dominated by the jagged, uplifted San Rafael Reef, which has nearly two dozen major canyons and many side draws and box canyons. The Reef’s crests rise between 800 and 1500 feet above the nearby desert flats. Two rivers meander and slice through the Reef on their way to the Green River. The Swell is filled with the history of cowboys, outlaws and ancient Indians and rockhounding areas abound. Three Grand County Travel Council brochures: “A guide to I-70”, “Recreation Guide to the San Rafael Area” and “San Rafael Desert Loop Auto Tour”, provide more detailed information on this area.

Once you get to know it, the Swell is a great place. An extensive network of dirt roads, built by prospectors and miners in the 1950s, provides pretty reasonable access. During the Spring, Fall and Winter, the weather can be pleasant, and there are a wide variety of canyons to check out. During the summer, the sun is unrelenting, and the choice of survivable adventures is few. The eastern edge of the Swell is sharply defined by the San Rafael Reef - a Navajo and Wingate sandstone bluff that rises out of the desert for 50 miles from near Price almost to Hanksville. Behind the Reef is the center of the Swell - an area dominated by flat layers of Coconino Sandstone, canyons cut into the rock, and bluffs that stand above the terrain.

Another view of the unique landscape

Between the towns of Salina and Green River, Interstate 70 cuts through a great dome of uplifted sedimentary rock called the San Rafael Swell. Fifty miles long and thirty miles wide, the Swell rises 1,500 feet above the surrounding desert, forming one of the scenic and geological wonders of the world. The San Rafael Swell is a world of jagged cliff faces, narrow slot canyons, and hidden valleys littered with domes and towers. Its landscape is an encyclopedia of earth history, displaying diverse exposed rock formations and erosional forms. It is a popular destination for hikers, climbers, and river runners. But the scenic beauty and historic solitude of the Swell is increasingly threatened by mineral exploration and indiscriminate off-road vehicle use.

Factory Butte Photo copyright James Kay

The Utah Wilderness Coalition's 752,900-acre wilderness proposal would safeguard the region now and complement any additional protections that may be afforded through National Park designation.

The Geology Exposed

Moroni Slopes Photo copyright James Kay

The San Rafael Swell is a microcosm of the entire Colorado Plateau: a huge basin ringed by highlands, studded with mesas and buttes, traversed by powerful, sediment-laden desert streams, and crisscrossed by canyon systems. Because uplift and erosion have been greater in the interior, the oldest rock formations are exposed in the core of the Swell, surrounded by concentric rings of younger rocks which radiate outward like waves in a pond.

Each rock formation has created its own unique world. In the heart of the Swell, two perennial streams have bored deeply into the rising land, revealing one of the oldest rock layers exposed in the region -- the 250 million-year-old Coconino Sandstone. So narrow are these canyons, called "The Chute" and "The Black Box," that flood debris hangs from their walls 30 to 50 feet above the canyon floor.

Above the Coconino lies the Kaibab Limestone, a resistant layer which forms the broad floor of Mexican Bend, the hidden valley where the outlaw Butch Cassidy once left two posses eating his dust. Above the Kaibab lie the red beds of the Moenkopi and Chinle formations, forming the intricate, spired redrock mazes of Red Canyon, Penitentiary Canyon, and Keesle Country. Above the Chinle rise the petrified sand dunes of the Wingate, Kayenta, and Navajo formations. Smooth, hard, elegantly sculptured masses of bare rock, these formations form the great outer wall of the San Rafael Reef and the huge, monolithic buttes and towers in the interior of the Swell.

The rock formations collectively named the San Rafael Group lie for the most part outside the Swell. They include the colorful Entrada Sandstone, which forms the brilliant orange cliffs and towers of Cathedral Valley, Salt Wash, and the Red Desert, and the famous hoodoos of Goblin Valley, just south of the Swell. Higher still lie the psychedelic badlands of the Morrison Formation, an intricate "painted desert" littered with agate, chert, barite, celestite, geodes, gastroliths, dinosaur bones, and glittering shards of gypsum. South and west of the Swell, dark volcanic mountains loom over the badlands, radiating knife-sharp dikes, or fins, of jet-black basalt. And above all this, forming a sea of blue-grey hills to the south and east of the Swell, lies the Mancos Shale, at 65 to 100 million years the youngest rock in the region.

Assembly Hall Peak Photo copyright David Muench

Habitat for Wildlife and Adventurers

This rugged and varied terrain supports an exceptional variety of wildlife. In recent years, the Utah Department of Wildlife Resources (UDWR) has established a population of more than 70 bighorn sheep in the Swell. The UDWR estimates the total carrying capacity of the Sids and Mexican Mountain WSAs alone at nearly 2,000 sheep. More than 300 pronghorn antelope occupy the desert east of the Swell, occasionally venturing into its interior (BLM, 1986). In the jagged cliffs ringing Mexican Mountain, the UDWR has identified more than 11,000 acres of critical peregrine falcon habitat.

Not surprisingly, the San Rafael Swell also provides critical habitat for climbers, hikers, and boaters. Just three hours' drive south of Salt Lake City, the Swell is the nearest and most accessible part of southern Utah's canyon country for residents of the Wasatch Front. Its attractions are featured in at least six different guidebooks. Since 1986, Utah publishers have released three new books about the Swell, one of which describes more than 300 miles of hiking routes inside Utah Wilderness Coalition-proposed wild lands. By the turn of the century, according to BLM estimates, non-motorized recreation in the Swell could increase to more than 10 times its current level.

More Geology

The western slope of the Swell is more gradual, eroding into canyons, spires, and castles.	Black Dragon Wash
	In the Tertiary Period (beginning 65 million years ago), the western side of the US was lifted up. The Great Basin fell and stretched away from the Colorado Plateau. (This plateau includes the San Rafael and Moab areas.) Powerful erosion began to wash the rock layers away. Once the Cretaceous Period deposits were eroded, the original uplifted region broke the surface again.
	As the "blister" broke, the reef edge was exposed. Some highlands were protected by hard underlying rock layers, forming large flat areas. Deep gorges were cut through the harder rock as water drained from the uplifted areas.
Where a small bit of hard rock was spared in a higher layer, castles and spires were left standing. This occurs where Kayenta protects the underlying Wingate, or when Navajo sandstone is capped by a harder layer of Carmel. These spires are the Twin Priests, composed Navajo sandstone along the Devil's Racetrack.	Devil's Racetrack
A Deep Gorge	The result of the erosion is a dynamic and varied landscape of open vistas, castles and spires, cliffs, deep gorges, and beautiful rock -- today's San Rafael. Although remote from civilization, and largely unknown by mountain bikers, the San Rafael Swell offers some great experiences.