Geology

Home to all of Utah's national parks, the Colorado Plateau is one of the geologic features that defines the West. No wonder this land of canyons, desert towers and hoodoos so often sits center stage in Hollywood Westerns and Wile E Coyote cartoons. The rise of the plateau, coupled with the effects of a million years of erosion by sand, wind and rivers, is fundamental to understanding the striated geologic history of Utah's national parks.

Beautiful Utah

With arches, buttresses, hoodoos, fins, narrows, canyons and spindly wind-whipped towers, Utah offers up iconic glimpses into the Earth's violent and fascinating geological history. Here you can travel through time as you journey past layer-upon-layer of sandstone, gape at delicate arches or just sit and wonder how a river could carve a canyon so deep and so elegant.

The Colorado Plateau

The Colorado Plateau extends for 337,000 sq km through portions of Utah, Colorado, New Mexico and Arizona. Evidence of its long-term stability is readily apparent in the horizontal layers of sediment that have changed little from the day they were laid down. But to the west, the thinning and stretching of the earth’s crust has been so vigorous that mountain ranges have collapsed onto their sides and entire valleys have fallen thousands of feet. To the east, colliding forces have crumpled the land to form the Rocky Mountains.

Starting out as a shallow basin collecting sediment from nearby mountains, the entire Colorado Plateau was uplifted some 60 million years ago. At that time, the plateau split along deep cracks called faults. Over hundreds of thousands of years, these cracks have eroded to form stupendous cliffs that subdivide the Colorado Plateau into several smaller plateaus. Along the western edge, for example, a line of high, forested plateaus tower 3000ft above desert lowlands and valleys. Nicknamed the High Plateaus by geologist Clarence Dutton in 1880, the term encompasses the flat-topped mesas of Zion and Bryce Canyon National Parks and also Cedar Breaks National Monument.

From an aerial perspective, these lofty plateaus and cliffs form a remarkable staircase that steps down from southern Utah into northern Arizona. Topping this so-called ‘Grand Staircase’ are the Pink Cliffs of the Claron Formation extravagantly exposed in Bryce Canyon. Below them jut the Gray Cliffs of various Cretaceous formations. Next in line are the White Cliffs of Navajo sandstone that make Zion Canyon justly famous. These are followed by the Vermilion Cliffs near Lees Ferry, Arizona, and finally come the Chocolate Cliffs abutting the Kaibab Plateau and Grand Canyon.

Another way of understanding the Grand Staircase is to visualize that the top layers of exposed rock at the Grand Canyon form Zion’s basement, and that Zion’s top layers in turn form the bottom layers of Bryce Canyon National Park. Geologically speaking, one can imagine the parks as being stacked on top of each other. Hypothetically, a river cutting a canyon at Bryce would eventually form another Zion Canyon, and then over time create another Grand Canyon.

A Four-Act Play

Perhaps the simplest way to approach the geologic story of the Colorado Plateau is to think of it as a four-act play. The first act features sedimentation, followed by lithification, then uplift and, finally, erosion. While this is an oversimplification, and there’s overlap between the scenes, it offers a framework for understanding the region’s geologic history.

More than 250 million years ago, the Colorado Plateau country was a shallow sea off the west coast of the young North American continent (which at the time was merged with other continents into a giant supercontinent known as Pangea). This time period, known as the Paleozoic Era, marked the dramatic transition from primitive organisms to an explosion of complex life-forms that spread into every available niche – the beginning of life as we know it. Fossils, limestone and other sediments from this era now comprise nearly all exposed rocks in the Grand Canyon, and they form the foundation that underlies all of the Colorado Plateau.

At the close of the Paleozoic, the land rose somewhat and the sea mostly drained away, though it advanced and retreated numerous times during the Mesozoic Era (250 million to 65 million years ago). Sedimentation continued as eroding mountains created deltas and floodplains, and as shallow seas and tidal flats left other deposits. Meanwhile, the rise of an island mountain chain off the coast apparently blocked moisture-bearing storms, and a vast Sahara-like desert developed across the region, piling thousands of feet of sand atop older floodplain sediments. Zion’s monumental Navajo sandstone cliffs and Arches’ soaring spans of Entrada sandstone preserve evidence of mighty sand dunes.

Over millions of years the weight of the accumulated layers (more than 2 miles thick) compacted loosely settled materials into rocks cemented together with mineral deposits – a process called lithification. Sandstone, siltstone and mudstone are each cemented together with calcium carbonate. Variations in particle size and quantities of cement account for these layers’ differing strengths – weakly bonded rocks crumble relatively easily in water, while more durable rocks form sheer cliffs and angular blocks.

Then came the uplift. About 60 million years ago North America began a dramatic separation from Europe, sliding west over another part of the earth’s crust and leaving behind an ever-widening gulf in the Atlantic Ocean. This movement caused the continent’s leading edge to uplift, forever transforming the face of the continent by raising the Colorado Plateau more than a mile above sea level. Though the plateau avoided the geologic turmoil that deformed much of western North America, the forces of uplift did shatter the plateau along fault lines into stair-step subplateaus. Furthermore, the creation of the Rocky Mountains provided headwaters for great rivers that would chisel their way through the newly risen plateau in their rush to the sea, forming the great canyons we see today.

In fact, nearly every aspect of the Colorado Plateau landscape is shaped by erosion. Several factors make the forces of erosion particularly dramatic in the Southwest. First are the region’s colorful rock layers themselves. As these layers rose, gravity enabled watercourses to gain momentum and carve through stone, while sporadic rainfall and an arid climate ensured the soft layers would otherwise remain intact. These factors have remained consistent over millennia, enabling fragile hoodoos, fins and arches to develop.

Water is by far the most dramatic shaping force. Flash floods tear through soft rock with immense power, tumbling house-sized boulders down narrow slot canyons and scooping out crumbling sediments like pudding. Those who witness summer thunderstorms will notice how quickly desert waters turn rust-red with dissolving sedimentary rock. Zion’s Virgin River has been described as ‘a red ribbon of liquid sandpaper’ due to its relentless downward gouging.

As the rocks’ calcium-carbonate cement dissolves in rainwater, it releases sand particles and flows down rock faces, then hardens again as it dries, leaving drippings that look like candle wax – a common feature on rock faces in both Zion and Bryce Canyons. Over time this leaching away of the cement also widens cracks and creates isolated fins that further split and dissolve into hoodoos, windows, arches and other fantastic forms, as seen in all of southern Utah’s parks.

In winter, storm erosion works in tandem with another equally powerful force. As rainfall seeps into cracks, it freezes and then expands with incredible pressure (sometimes over 20,000lb per square foot), pushing open crevices and prying loose blocks of stone. At higher elevations such as Bryce Canyon, this freeze–thaw cycle is repeated more than 200 times each year, exacting a tremendous but ultimately beautiful toll on the natural landscape.

Reading the Parks

It’s a complex geologic tableau that characterizes the national parks of southern Utah, from Arches to Zion. In a sense it’s a remarkably homogenous region, but at the same time, the forces of erosion have carved an amazingly intricate and diverse landscape that’s difficult to comprehend. Each park and national monument reveals an astonishing geologic story that goes far beyond the scope of this brief introduction.

Zion National Park

Part of southern Utah’s High Plateaus district, Zion sits on the southwest corner of the Colorado Plateau, marking the transition from relatively stable plateau country to the more tectonically active Great Basin. Separating these distinct regions is a long line of cliffs along the Hurricane Fault.

In Zion Canyon, massive cliffs expose over 2000ft of Navajo sandstone, formed by ancient sand dunes. Nowhere else in the world do these rock formations reach such grand heights. Meanwhile, in the park’s Kolob Canyons area, sheer cliffs jut abruptly from the Hurricane Fault as if they rose out of the ground just yesterday. The reddish coloration of all of these cliffs is caused by iron oxides. In the more freshly exposed rocks of Kolob Canyons, the red is evenly distributed. More oxides have leached out of Zion Canyon’s ancient weathered cliffs, however, leaving the uppermost layers whitish.

Bisecting the national park, the Virgin River continues its steady march – cutting downward about 1000ft every million years – so rapidly, in fact, that side tributaries can’t keep up and are left as hanging valleys high on cliff faces. The dynamic interplay between Navajo sandstone and the underlying Kayenta Formation largely shapes Zion Canyon. Through the Narrows, for example, the Virgin River flows entirely between sandstone walls, but where it cuts deeply enough, the river readily erodes the softer shale underneath the sandstone cliffs and dramatically widens the canyon.

Bryce Canyon National Park

Bryce is not a canyon at all, but a series of amphitheaters gouged from the gorgeous Pink Cliffs. The park’s central Claron Formation results from soft siltstone and mudstone that settled to the bottom of a giant freshwater lake 60 million years ago. Traces of manganese and iron account for this layer’s fetching pink and orange hues. About 15 million years ago, the lakebed lifted, cracking from the stress along countless parallel joints, while further east the Aquarius Plateau rose even higher. The significant valley between the plateau and Bryce was carved by the Paria River, which over the past million years has begun to nip at the park’s cliffs.

Bryce features dramatic formations at all stages of development, from newly emerging fins to old weathered hoodoos beaten down into colorful mounds. Runoff along joints on the canyon rim forms parallel gullies with narrow rock walls, or fins, which ultimately erode into the isolated columns known as hoodoos. The layers are so soft that in heavy rains they would quickly dissolve into muddy little mounds, except that siltstone layers alternating with resistant limestone bands give the layers strength as they erode into towering hoodoos. Many hoodoos end up with a cap of harder limestone at their apex, protecting the softer material beneath.

Grand Staircase–Escalante National Monument

This vast, complex region contains examples of nearly every rock type and structural feature found in the Colorado Plateau country. Revealed here are more than 200 million years of geologic history and one of the world’s most exceptional fossil records of early vertebrate evolution. The entire period that dinosaurs ruled the earth is preserved in remarkable detail. Grand arches, waterfalls, slot canyons, sculpted sandstone cliffs and challenging terrain make this a memorable place to visit.

The monument encompasses its namesake feature, the Grand Staircase, on its western edge. Over a dozen different geologic layers document Mesozoic seas, sand dunes and slow-moving waters that once teemed with abundant ancient life. Examples range from the lavender, rose, burgundy and peach colors of volcanic ash and petrified forests of the Chinle Formation to the ancient sand dunes preserved in the bluffs of Wingate sandstone at Circle Cliffs.

Few other features characterize this place like the celebrated slot canyons of the Escalante River, carved by fast-moving waters entrenched in resistant sandstone channels that cut downward rather than spreading outward. At their upper ends these canyons modestly wind through the slickrock like tiny veins before feeding into increasingly larger arteries that eventually empty into the Colorado River.

Capitol Reef National Park

Here, along a narrow, 100-mile stretch, the earth’s surface is bent in a giant wrinkle, exposing multiple rock formations in tilted and upended strata. It's a unique geological feature of the region, in that the relatively stable Colorado Plateau was twisted and pulled here. This type of step-up feature is known as a monocline, and the Waterpocket Fold is one of the longest contiguously exposed monoclines in the world. Incredibly, the rock layers on the west side have been upended more than 7000ft higher than those to the east. Dubbed a reef by early explorers, who found it a barrier to travel, the fold is capped with bare rounded domes of Navajo sandstone reminiscent of the US Capitol building from the 1850s – hence the name Capitol Reef.

While just a few major canyons cut across the Waterpocket Fold, a baffling maze of side canyons crisscrosses the park in myriad directions. All formed along clefts and other weak points in the rock, where moisture collects (natural pools of water atop the fold account for its name) and eventually scours out ever-expanding gullies. Another sandstone layer, the Wingate Formation, gives the Waterpocket Fold a line of distinctive sheer red cliffs on its west side. A third sandstone layer, Entrada sandstone, forms the freestanding pinnacles and walls of Cathedral Valley.

Other formations add so much color and structural diversity that this park is considered without equal in a region chock-full of geologically impressive parks.

Canyonlands National Park

Canyonlands is defined by the mighty Colorado and Green Rivers. Although the rivers have already carved through 300 million years of the earth’s history, only the oldest 125 million years’ worth of rock layers remain – a staggering testament to the power of erosion. When you gaze into the canyon depths from Grand View Point at the Colorado River, you’re only looking at the middle slices of a giant geologic cake, with the top layers eaten away and the bottom layers still unseen.

Canyonlands is even more diverse than the Grand Canyon, possessing not just two converging river canyons, but intervening high mesas and a complex landscape of slickrock canyons, spires and arches. Cradled between the Green and Colorado Rivers, the Island in the Sky mesa is a tableland of Wingate sandstone topped with scattered buttes and domes of Navajo sandstone. Below the mesa, slopes plunge 2000ft to the rivers past a shelf of White Rim sandstone partway down. The rivers twist and turn along meandering paths inherited from the Miocene epoch (about 10 million years ago), when the land was still a flat plain.

To the south, you'll find the Needles, where colorful red and white bands showcase a complicated, 250-million-year-old history of retreating and advancing shallow seas. The red layers formed in river flooding after the sea’s retreat, while white layers represent ancient beaches and coastal dunes. To the west lies the Maze, an almost incomprehensibly convoluted landscape explored by backcountry adventurers.

In many parts of Utah, red cliffs appear to be stained black by a thick coating of desert varnish. Composed of clay minerals, oxides and hydroxides of manganese and iron, this patina is formed very slowly (even for geological time) and is instrumental in dating rock formations. It also provides the canvas on which many of southern Utah's petroglyphs have been carved.

Arches National Park

Compared to the other parks, Arches’ geologic makeup is relatively easy to understand. Ancient rock layers rose atop an expanding salt dome, which later collapsed, fracturing layers along the dome’s flanks. These cracks then eroded along roughly parallel lines, leaving fins of freestanding Entrada sandstone. In the last 10 million years, erosion has removed roughly a vertical mile of rock, carrying away all older materials save for the freestanding fins. This process continues today: even as brittle arches occasionally collapse, new ones are always in the making.

An arch formation is more a matter of happenstance than a predictable pattern, as people pay scant attention to the countless ‘almost’ arches that crumble into oblivion. But in a few lucky cases, rock slabs flake from the sides of fins in just the right way to create small openings that grow into arches as water seeps into cracks, freezes and dislodges more pieces.

At times the rock itself assists by releasing tremendous internal pressures stored within its layers, which causes more slabs to pop off. The uniform strength and hard upper surfaces of Entrada sandstone are the perfect combination for creating such beautiful arches, and today this park has the world’s greatest concentration of natural stone arches.

Sidebar Did You Know?

Zion’s soaring cliffs were once humongous sand dunes – look closely for fine diagonal lines of cross-bedding, the marks of ancient winds that once swept the dunes.

Sidebar: 1

One of the best views of the Grand Staircase lies along Hwy 89A between Kanab, Utah, and Jacob Lake, Arizona, where the steps rise dramatically.

Sidebar: 2

Singing Stone: A Natural History of the Escalante Canyons (1999), by Thomas Fleischner, brings the geology of Grand Staircase–Escalante National Monument into understandable, human terms as it examines the land controversies of the New West.

Sidebar: 3

Glen Canyon was flooded in 1963, forming Lake Powell. The Sierra Club had blocked the creation of the dam in nearby Dinosaur National Monument, paying less attention to Glen Canyon.

Sidebar: 4

Armchair explorers can take a virtual field trip to southern Utah, or learn where to find dinosaur tracks, on the Utah Geological Survey’s website (http://geology.utah.gov).

Sidebar: 5

Challenging Basin & Range (1981), by Pulitzer Prize–winning writer John McPhee, is as much about the journey through, as the geology of, the Great Basin, which covers much of western Utah, Nevada and eastern California.

Sidebar: 6

Roadside Geology of Utah (1990), by Halka Chronic, is an invaluable companion for geology buffs, aspiring and otherwise. By the end of your trip, you’ll never confuse your Navajo and Entrada sandstones again!

Sidebar: 7

Dive deeper into the geology of Utah and the Colorado Plateau, with history, hiking and interactive map features on www.utahgeology.com.

Sidebar: 8

Among the piles of slick picture books, Water, Rock & Time (2005), by Robert L Eves, stands out. It pairs colorful illustrations and photos with eloquent writing and clear descriptions of Zion’s geology, accessible for everyone.

Sidebar: 9

A technical and colorful overview of the region’s rocks is provided in Geology of Utah’s Parks & Monuments (2010), published by the Utah Geological Association, and edited by Douglas Sprinkel and a team of specialists.

Sidebar: 10

Capitol Reef has lots to interest amateur paleontologists, including North America’s oldest predinosaur megatrack site, plant megafossils and a 100-million-year-old oyster reef.

Sidebar: 11

Arches National Park has 2000 known arches within its boundaries, ranging in size from just 3ft to over 300ft wide; the largest is Landscape Arch.

Wildlife

The Colorado Plateau’s harsh and arid landscape asks a lot of the plants and animals that make their homes here. Rains are few and far between, habitable terrain is limited, smaller washes evaporate quickly while rivers are separated by hundreds of miles, and the temperature shifts are dramatic. This said, many specialized plants and animals have found remarkable ways to survive and adapt to life on the plateau.

Animals

Wildlife in southern Utah’s parklands ranges from nimble bighorn sheep and speedy raptors to scampering lizards and nosy ringtail cats, all scattered across a vast and wild region. Only rarely do animals congregate in large or conspicuous numbers, however. During the hottest days of summer, most animal activity takes place in the early evening or at night, when temperatures drop. Bird-watching is a particularly rewarding activity in southern Utah.

Large Mammals

Desert bighorn sheep stand guard on inaccessible cliff faces, mule deer and elk wander through mountain meadows, and mountain lions lurk in the forest, but your chances of seeing such large mammals are relatively slim. They may show up when you least expect them, so keep your eyes open!

Mountain Lions

Even veteran wildlife biologists rarely see a mountain lion, though a fair number reside in canyon country. Like their favorite prey, mule deer, mountain lions mostly inhabit forested areas. Reaching up to 8ft in length and weighing as much as 175lb, these solitary animals are formidable predators that rarely bother humans. A few attacks have occurred in areas where human encroachment has pushed hungry lions to their limits, mainly around rapidly growing towns and cities.

Mule Deer

Forests and meadows are the favored haunts of mule deer, which typically graze in the early morning and evening. Uncommon when settlers first arrived, and soon hunted out, mule deer nearly vanished around the turn of the 20th century, then quickly rebounded as their predators were eliminated.

Bighorn Sheep

Like solemn statues, desert bighorn sheep often stand motionless on distant cliff faces or ridgelines, distinguished by their distinctive curled horns. During the late-fall and early-winter breeding season, males charge each other at 20mph and ram horns so loudly that the sound can be heard for miles.

Small Mammals

Small mammals are more abundant than their larger cousins, and many types of squirrels, chipmunks and small carnivores can be spotted around the parks’ campgrounds and picnic areas and along hiking trails.

Chipmunks & Squirrels

Several species of small, striped chipmunks and ground squirrels are ubiquitous in the parks. The white- and brown- or black-striped Uinta chipmunk is especially common along the canyon rim in Bryce and on Zion’s forested plateaus. Though it resembles a chipmunk, the golden-mantled ground squirrel lacks facial stripes. Both species scamper through the forest, searching for nuts and seeds. They also beg for handouts – and occasionally run off with unattended sandwiches – but resist the urge to feed them.

On open desert flats you’re more likely to see the white-tailed antelope squirrel, one of the few mammals active during the daytime. Look for its white tail, which it carries over its back like a reflective umbrella, shielding it from the sun as it darts between shady patches. True to its name, the speckled gray rock squirrel nearly always inhabits rocky areas. This large, bold squirrel often visits campgrounds.

Beavers

Some of the first Western explorers to wander across the Colorado Plateau came in search of prized beaver pelts. Limited to the few large rivers, beavers have never been common in southern Utah, but they are frequently sighted, because most visitors flock to the parks’ rivers. In Zion their persistent nocturnal gnawing on large cottonwood trees presents something of a quandary. Wire mesh protects the base of some trees, but the park must still address the bigger question of how to restore the original balance of beavers, spring floods and cottonwoods that existed before humans forced the river into its current channel.

Porcupines

Looking much like an arboreal pincushion, the porcupine spends its days sleeping in caves or the hollows of trees in piñon-juniper woodlands. It’s easy to overlook this strange creature, though on occasion you might encounter one waddling slowly through the forest. It’s most active at night, when it gnaws on the soft inner wood of trees or pads around in search of flowers, fruit, nuts and berries.

Ringtail Cats

One of southern Utah’s most intriguing creatures is the nocturnal ringtail cat, which looks like a masked chihuahua with a raccoon tail. It preys on mice and squirrels, but will eat lizards, birds or fruit in a pinch. Fairly common in rocky desert areas, ringtails may appear around campsites at night, though they are generally timid and secretive.

Wood Rats

Although they bear a superficial resemblance to city rats, wood rats are extraordinary, gentle creatures. The Colorado Plateau’s species all share a maddening propensity for stealing small shiny objects like watches or rings and leaving bones, seeds or other small objects in exchange – hence the animal’s common nickname, the pack rat. Wood rats build massive stick nests (middens) that are used by countless generations. Upon dismantling these middens and examining their contents, biologists have been able to document more than 50,000 years of environmental prehistory in the region.

Birds

Whether you get a thrill from watching the high-speed dives of white-throated swifts and peregrine falcons from atop towering cliffs, or the bright songs of canyon wrens echoing across the plateau, there’s no question that southern Utah’s 250-plus bird species are among the region’s top highlights.

Small Birds

The first birds many people encounter are white-throated swifts, which swoop and dive in great numbers along cliff faces and canyon walls. Designed like sleek bullets, these sporty ‘tuxedoed’ birds seem to delight in riding every wind current and chasing each other in noisy, playful pursuit. Flying alongside the swifts are slightly less agile violet-green swallows, a familiar sight around campgrounds and park buildings. Both species catch their food ‘on the wing.’

One bird with a unique call is the blue grouse. This resident of mountain forests vocalizes from the ground and has such a deep call that you almost feel it in your bones. Most sightings occur when a startled grouse erupts from your feet into flight. On rare occasions you may spot a male as it puffs up its chest and drums to attract a female.

The stirring song of the canyon wren is, for many people, the most evocative sound on the plateau. So haunting is the song it hardly seems possible that this tiny rust-red rock-dweller could produce such music. Starting as a fast run of sweet tinkling notes, the song fades gracefully into a rhythmic cadence that may leave you full of longing.

In contrast, the garrulous call of the Steller’s jay can grate on your nerves like a loud rusty gate. But this iridescent blue mountain bird makes up for it with wonderfully inquisitive and confiding mannerisms. It often seems to have no fear of humans and eagerly gathers around picnic tables and campsites, hoping for leftovers – keep these birds wild by not giving them handouts or any other encouragement to beg.

Another common forest dweller is Clark’s nutcracker, a grey bird with black wings and tail. Its highly specialized diet consists almost entirely of pine nuts, which it pries out of thick pine cones using its downturned bill like a crowbar. These birds may deposit up to 1000 ground caches of nuts in a single year, making its feeding habits integral to the survival and propagation of mountainous pine forests.

Rafters and riverside hikers will almost certainly meet the brilliant blue grosbeak, with its loud, long musical warbles. This migratory bird scours dense thickets for tasty insects and grubs, and males often ascend to high perches to defend their territory. The American dipper is often seen bobbing its head to snap up underwater insects, especially in Zion’s Virgin River. This medium-sized gray fellow is North America’s only true aquatic songbird, ably swimming in rapidly rushing rivers (without webbed feet!) to feed.

Large Birds

Of the various owls that reside on the Colorado Plateau, none is as familiar as the common and highly vocal great horned owl, which regularly fills the echoing canyons with its booming ‘hoo-hoo hooo hooo’ calls. This is among the largest and most fearsome of all raptors, and when one moves into the neighborhood, other owls and hawks hurry on to more favorable hunting grounds or run the risk of being hunted down as prey themselves. This bird’s glaring face and prominent ‘horns’ (actually erect tufts of feathers) may startle hikers as it peers down at them from a crevice or dark cavity.

The threatened Mexican spotted owl has garnered considerable media coverage over the years. In California and the Pacific Northwest, this owl nests solely in old-growth forests, which are being logged, and climate change is affecting its habitat in the Southwest. The subspecies that lives on the Colorado Plateau makes its home in Utah’s rugged canyons and mountain forests. Sightings are rare – there are only 2000 left in the US – but thrilling.

Commanding vast hunting territories of some 60 sq miles, powerful golden eagles are typically observed in passing as they travel widely in search of jackrabbits and other prey (up to the size of an adult deer). Watch for the characteristic golden tint on the eagle’s shoulders and neck. Boasting a 7ft wingspan, it is among the area’s largest birds, second in size only to reintroduced California condors. California condors are often confused with common turkey vultures. You can tell these fellow scavengers apart by the coloration on the undersides of their wings. Turkey vultures (or ‘TVs’) have black wings, with white tips. California condors also have black wings, but with white triangular-shaped patches on their undersides.

Despite their endangered status in recent decades, peregrine falcons thrive throughout the region, especially in Zion Canyon. There they find plenty of secluded, cliffside nesting sites, as well as one of their favorite food items, white-throated swifts, which they seize in midair. Look for the falcon’s long, slender wings and dark ‘moustache.’

Visitors may be surprised to see wild turkey. Formerly hunted out, this flashy game bird has been making a slow comeback in areas where it’s protected, particularly in Zion Canyon. In the spring mating season, males fan out their impressive tails and strut around to impress females.

Amphibians & Reptiles

Amphibians

Bleating choruses of common canyon tree frogs float up from boulder-strewn canyon streams each night. Gray-brown and speckled like stone, these tiny frogs dwell in damp crevices by day, emerging at night (and sometimes late afternoon) to sing beside rocky pools. Occupying a similar habitat is the aptly named red-spotted toad, a small species with red-tipped warts covering its body. Its nighttime song around breeding pools is a high, persistent musical trill.

More secretive, and thus rarely encountered, is the tiger salamander, the region’s only salamander. Spending the majority of its life in a burrow, this creature emerges when abundant water triggers its breeding cycle. In order to fully develop, a larval salamander requires a water source, although some larvae never change into the adult form and become sexually mature while still in the larval stage. Coloration varies by region, but most are blackish all over.

Lizards

Perhaps the region’s most abundant and widespread reptile is the eastern fence lizard, a small creature you’ll probably see perched atop rocks and logs or scampering across the trail. During breeding season, males bob enthusiastically while conspicuously displaying their shiny blue throats and bellies. Females have dark, wavy crossbars on their backs and only a pale bluish wash underneath.

Bold in comparison is the greenish collared lizard, a large-headed species with striking black bands around its neck. This fearsome lizard eats just about every small animal it can overpower. Because it has little to fear, it often perches conspicuously atop large boulders, scanning for movement in all directions. Like most of southern Utah’s lizards, it’s inactive during the coldest winter months.

You may also encounter the curiously flattened horned lizard, which looks like a spiny little pancake. This lizard’s shape is an adaptation to its exclusive diet of ants. In order to survive on this nutrient-poor diet, the horned lizard must eat lots of ants and consequently has an extremely large stomach that lends it its short, round appearance. Its shape also makes it harder for predators to grasp its body.

Snakes

The Colorado Plateau is excellent habitat for snakes, though visitors seldom encounter more than a few resident species. Most common is the gopher snake, easily mistaken for a rattlesnake because it hisses and vibrates its tail in dry leaves when threatened. Sporting a tan body with dark brown saddles, this 6ft to 8ft constrictor preys upon rodents, small birds, lizards and even the offspring of other snakes.

Nothing compares to the jolt of terror and adrenaline prompted by the angry behavior of a rattlesnake. Both humans and wild animals react with instinctive fear, even though rattlesnakes rarely strike unless provoked. These mild-mannered creatures would rather slide away unharmed than provoke a confrontation. A few species reside in the region, but only rarely does a visitor get close enough to tell them apart.

Another snake that keeps its distance is the striped whipsnake. This extremely slender 3ft to 6ft snake moves like lightning when alarmed and can climb into trees and bushes so quickly it seems like it’s falling away from you. The snake uses this speed to capture lizards and rodents.

Fish

The Colorado River and its tributaries were once home to at least 14 native fish species, nearly all of them unique to these waters and highly adapted to extreme conditions. After the introduction of grazing, dams and other artificial changes to the landscape, dozens of introduced species are now outcompeting these native fish.

One representative native species is the threatened Colorado pikeminnow, North America’s largest minnow (it can weigh up to 25lb and reach over 3ft in length). Once so abundant that it was pitchforked out of irrigation canals, the pikeminnow is in drastic decline, as many artificial dams block its 200-mile migration route. Three other endangered fish, the humpback chub, bonytail and razorback sucker, suffer similar fates. It’s unclear whether they will survive the changes being made to the rivers.

Potholes

A miracle of life unfolds wherever desert rains accumulate in what seem like lifeless, dusty bowls among the rocks. Hiding in the dust are the spores and eggs of creatures uniquely evolved to take advantage of ephemeral water. Within hours of rainfall, crustaceans, insects, protozoa and countless other organisms hatch and start swimming in this brew of life. Though most are microscopic or very small, there are also oddly shaped, 1in to 2in tadpole shrimp that resemble prehistoric trilobites.

Toads and frogs arrive the night after a rain and lay eggs that hatch quickly. Unlike amphibians in other areas, which can take months or years to develop, these tadpoles are champion athletes that emerge from the water in two to three weeks. No matter how productive a pothole may seem, however, its lifespan is limited by evaporation. All too soon, water levels drop, and everything turns to dust again. By then all the organisms have retreated into dormancy to wait for the next drenching rainstorm, which may be months or even years away.

Because each pool is a fragile ecosystem, hikers should exercise special care when they find a pothole. If necessary, remove only a little water, and don’t jump or swim in the water, because body oils, sunscreens and insect repellents can harm resident life. These creatures have nowhere else to go! Even when dry, these pools need our attention because the ‘lifeless’ dust is actually full of eggs and spores waiting to spring into life again.

Life Zones

Dominating southern Utah’s parks, desert scrub is the hot, dry zone below 4000ft where scraggly shrubs cling to life on sandy flats. The most common are low-growing blackbrush, shadscale, Mormon tea and sagebrush. Annual precipitation is likely to average less than 8in, a number that includes winter snows as well, so it isn’t very much rain, and most of it ends up running over bare rocks and washing away before plants can even use it.

Another widespread habitat is the open woodland of piñon pine and Utah juniper. Piñon-juniper woodland (‘P-J’ for short) grows mostly between 4000ft and 7000ft. Due to competition for water, trees are spaced widely here, though they still provide shade for many understory plants, as well as food and shelter for many animals. In some areas the trees grow in distinct lines, following cracks in the rock where water gathers after rain.

Growing in a narrow band between 7000ft and 8500ft, ponderosa pine forest indicates the presence of increased rainfall at higher elevations. In Zion, however, ponderosa pines grow at lower elevations, because porous Navajo sandstone is full of water, demonstrating once again how water dictates where plants can grow in this region. Ponderosa pines thrive in Zion and Bryce Canyon (with a few stands in Grand Staircase–Escalante) but are absent in lower-elevation Capitol Reef, Canyonlands and Arches.

Boreal forest above 8500ft has much in common with Rocky Mountain forests, even supporting many of the same plants and animals. This is a zone of cool, moist woodland and rainfall that exceeds 20in a year, conditions that favor trees like spruce, Douglas fir and quaking aspen. This forest populates a few high mesas in Zion, but the best examples are found at higher elevations in Bryce Canyon, particularly at road’s end near Rainbow Point, where stands of ancient bristlecone pines survive.

Due to intensive grazing, the grassland that once covered much of this region has been largely replaced by desert scrub and alien weeds. Early Western explorers’ journals describe a lush grassy landscape, though you’d hardly know it today. In areas of deeper sand and soil, where shrubs don’t grow well, it’s still possible to find pockets of galleta and Indian ricegrass.

Readily available water supports another set of unique habitats, ranging from hanging gardens clustered around cliffside seeps to riparian woodland lining perennial creeks and rivers. The presence of water attracts many plants and animals to these habitats. Monkey flowers, columbines and ferns mark spots where springs flow from sandstone cliffs. Riverbanks that were once home to majestic cottonwood and willow stands are more likely today to harbor highly invasive tamarisk.

Plants

The Colorado Plateau’s complex landscape supports an equally diverse mix of plant species. Many are specific to the plateau, while others are drawn from adjacent biological zones such as the Great Basin, Mojave Desert and Rocky Mountains. Each park and monument boasts a list of hundreds of species, and no two places are alike.

Most species are adapted in some way to the Southwest’s arid environment, either lying dormant until rains arrive or toughing it out through dry spells. If you arrive in wet season or after a drenching rain, you may be lucky enough to witness the region in its full splendor, when flowers carpet the landscape in all directions.

What you’ll witness more often, however, is the plodding life of plants that struggle to conserve every molecule of precious liquid. Many plants sport hairy or waxy leaves to prevent evaporation, while others bear tiny leaves. At least one common plant, Mormon tea, has done away with water-wasting leaves altogether and relies on its greenish, wiry stems for photosynthesis. Most species have long taproots to penetrate the soil in search of water.

The rapid rate of erosion on the Colorado Plateau also has a profound effect on the area’s ecosystems. Unlike other regions, where eroded materials accumulate and cover vast areas with homogenous soils, erosion on the plateau carries sediments away. Plants have nowhere to live except on freshly exposed bedrock, and because each rock layer has its own distinctive composition and chemistry, this profoundly limits the species that can grow there.

Biological soil crust is the living ground cover that forms the foundation of high desert plant life across the plateau. This black crust is dominated by cyanobacteria, but also includes lichens, mosses, green algae, microfungi and bacteria. It's the web that keeps the desert from eroding. Never step on these delicate living features.

Trees

Piñon pines are well known for their highly nutritious and flavorful seeds. These same seeds have long been a staple for Native Americans, and many animals also feast on the seeds when they ripen in the fall. Piñons bear stout rounded cones and short single needles. Together with Utah junipers, piñon pines form a distinctive plant community that covers millions of acres of Southwestern desert. Blue, berrylike cones and diminutive scalelike needles distinguish junipers.

Mingling with piñons and junipers in some canyons is the beautiful little Gambel oak, with its dark green leaves turning shades of yellow and red in fall and adding to the palette of color, particularly in Zion Canyon. Often growing in dense thickets, the oaks produce copious quantities of nutritious, tasty acorns long favored by Native Americans and used to make ground meal, breads, cakes and soups.

To identify the stately ponderosa pine, look for large spiny cones, needles in bundles of three, and yellowish bark that smells like butterscotch or vanilla. Between 20,000 and 12,000 years ago, the Douglas fir was one of the region’s dominant species, though today they are restricted to isolated mountaintops and north-facing slopes. This relict of an earlier time dramatically demonstrates how the region’s vegetation has changed since the last ice age. It’s identified by its single needles and cones with three-pronged bracts on each seed.

Found amid damp mountain meadows, quaking aspen is immediately recognizable by its smooth, white bark and circular leaves. Every gust of wind sets these leaves quivering on their flattened stems, an adaptation for shaking off late snowfalls that would otherwise damage fragile leaves. Aspen groves comprise genetically identical trunks sprouting from a common root system that may grow to more than 100 acres in size. By budding repeatedly from these root systems, aspens have what has been called ‘theoretical immortality’ – some aspen roots are thought to be more than a million years old.

Rivers and watercourses in this harsh desert landscape are lined with thin ribbons of water-loving plants that can’t survive anywhere else. Towering prominently over all others is the showy Fremont cottonwood, whose large, vaguely heart-shaped leaves rustle wildly in any wind. Hikers in the canyons’ scorching depths find welcome respite in the shade of this tree. In spring, cottonwoods produce vast quantities of cottony seed packets that fill the air and collect in every crack and crevice. Box elder is another common streamside plant. It issues winged, maplelike seeds and bears trifoliate leaves that resemble those of poison ivy.

Since 1920 the aggressive weedy tamarisk (salt cedar) has largely replaced native streamside plant communities. Though this delicately leaved plant from Eurasia and Africa sports a handsome coat of soft pink and white flowers through the summer, its charm ends there, for it robs water from the soil and completely overwhelms such native species as cottonwood and willow.

A special treat is a visit to the fruit orchards of Capitol Reef, where you can pick apples, peaches and cherries.

Shrubs

Blackbrush covers large tracts of Southwestern deserts. This dark shrub reaches great ages and is only rarely replaced by young seedlings. With wiry stems, shrunken leaves and yellowish-red petal-less flowers blooming only after heavy spring rains, it may look more dead than alive.

Also triggered by spring rains, the common cliff rose (or desert bitterbrush) paints rocky slopes with its white blossoms surrounding yellow stamens. You’re likely to ‘hear’ this plant before you see it, as bees and insects swarm to its acrid-smelling flowers. Though its resinous, leathery leaves taste bitter, deer still munch on the plant in winter.

Narrowleaf yucca is a stout succulent related to agave and century plants. Yuccas favor sandy sites, while blackbrush predominates on thin gravelly soils. Growing in a dense rosette of thick leaves, this plant sends up a 5ft stalk of creamy flowers. A night-flying moth pollinates these flowers; in exchange, the caterpillars eat some seeds. Native Americans used yucca fibers to weave baskets and sandals.

Ripening in summer, the juicy black canyon grape is a tart favorite food of many different kinds of mammals and nearly 100 species of birds. Its vines snake over bushes and rocks in damp canyons, particularly in Zion Canyon, where its maplelike leaves turn yellow, orange and red in the fall.

Another distinctive shrub is greenleaf manzanita, which flourishes in ponderosa pine forests along the rim of Bryce Canyon. It bears reddish-brown bark and equally smooth, quarter-sized leaves. Bees alight on its pale pinkish flowers, while mammals and birds feed on its dark-red fruit.

Wildflowers

A surprisingly large variety of wildflowers thrive in the Colorado Plateau’s arid, rocky landscapes. While late-winter precipitation and spring snowmelt trigger some plants to flower, many others bloom following midsummer thunderstorms or when temperatures cool in early fall.

Seeps, springs and stream banks host some of the most dramatic flower displays. The brilliant flash of monkey flowers amid greenery comes as something of a shock for hikers who’ve trudged across miles of searing baked rock. These red, yellow and purple flowers with widely flared ‘lips’ are very tempting to hummingbirds.

Columbines are also common at the seeps and springs, though some species range up into forested areas as well. The golden columbine and crimson-colored Western columbine are most common in wet, shaded canyon recesses. Rock columbine grows amid Bryce Canyon’s hoodoos, where its vivid blue flowers stand out against red-rock cliffs. The flowers of both species hold pockets of nectar that attract large numbers of butterflies and hummingbirds.

The showy prince’s plume boldly marks selenium-rich desert soils with a 2ft to 3ft stalk of dainty yellow flowers. By using selenium in place of sulfur to manufacture its amino acids, this plant renders itself poisonous to herbivores and grows in soils that other plants can’t tolerate. Prospectors once thought of this plant as an indicator of places to dig for uranium, as selenium deposits may naturally occur near uranium. Other wildflowers that do well on dry, gravelly slopes include stalky penstemon and paintbrush varieties, all with bright, showy tubular flowers in a rainbow of colors.

In peak years evening primroses are so abundant that it looks like someone scattered white tissues over the sandy desert. Turning from white to rosy pink, the small flowers open at sunset and close by morning, thus avoiding the day’s heat and conserving water. At night large sphinx moths dart from flower to flower, collecting nectar and laying eggs.

Blooming in late spring and early summer, the three-petaled sego lily is another white flowering plant that is also Utah’s state flower. Native Americans and early Mormon settlers once harvested the plant’s walnut-sized bulbs for food. Don’t confuse its small, delicate blooms with the large, showy white flowers of sacred datura, which blooms from spring through fall. This poisonous plant was traditionally used by some indigenous tribes during religious rituals as a potent hallucinogenic, but it can be deadly.

Other Plants

Among the most common cacti in southern Utah are those belonging to the prickly pear group, familiar for their paddle-shaped pads. Both the pads and fruit of the beavertail cactus were traditionally eaten by Native Americans after proper preparation. Be aware that the barbed, bristlelike hairs (glochidia) detach easily on contact and are highly irritating. Claret cup cacti shine like jewels in the dusty desert landscape, where they are the first to bloom in spring. Their deep scarlet flowers burst forth from up to dozens of stems per clump, blooming simultaneously for several days.

Maidenhair fern deserves special mention because it adds bright green coloring to countless desert oases. Lacy and delicate, this fern requires a continuous supply of water. You’ll recognize it by its leaves, arranged like an open hand from a central wiry black stem.

A close examination of juniper tree branches reveals an extremely abundant but easily overlooked plant – yellowish-green juniper mistletoe. Partially parasitic, but not harming its host trees, mistletoe produces tiny fruits that some birds prefer to feed on. Carried in the birds’ digestive tracts, the seeds adhere to new tree branches once excreted.

Formerly widespread across vast tracts of the desert, grasses like Indian ricegrass and galleta now survive only in relict patches. Along with this loss, an entire food chain of animals that relied on grasslands has also declined, evidenced by local extinctions of bears and wolves, for example. Bearing large nutritious seeds, ricegrass was also an important staple for Native Americans.

Sidebar: 1

National park visitor centers sell inexpensive, fold-out field-guide brochures so you can easily identify many of the local plants and animals you’ll see.

Sidebar: 2

A Naturalist’s Guide to Canyon Country (2000) by David Williams comes as close as possible to a complete beginner’s compendium – covering geology, birds, mammals, insects, reptiles, trees, wildflowers and more – primarily focusing on southeastern Utah.

Sidebar: 3

Utah’s Division of Wildlife Resources offers a free online field guide (http://dwrcdc.nr.utah.gov/ucdc/default.asp) to wildlife inhabiting the Beehive State, from big-eared bats to tiny lizards.

Sidebar: 4

An affordable, all-in-one companion on your desert travels, the National Audubon Society Field Guide to the Southwestern States (1999) is practically encyclopedic, covering everything from geology to astronomy to ecology, with over 1000 species identified.

Sidebar: 5

Eating Stone: Imagination and the Loss of the Wild (2006) by Ellen Meloy is as much a rumination on the politics of wilderness preservation as an admittedly anthropomorphic study of bighorn sheep, including in southern Utah.

Sidebar: 6

To learn some more about Bryce Canyon’s prairie-dog community, download the short podcast from the park’s official website at www.nps.gov/brca/photosmultimedia/podcasts.htm.

Sidebar: 7

Birds of Utah Field Guide (2003) by Stan Tekiela is great for beginning birders, with full-page photos and species descriptions helpfully organized by color and size.

Sidebar: 8

Curious about how endangered California condors are doing in southern Utah and northern Arizona’s canyon country? Get more information at www.nps.gov/grca/learn/nature/condor_updates.htm.

Sidebar: 9

Once threatened by extinction – and still a species of special concern in Utah – some bald eagles spend their winters in Zion and Bryce’s canyon country, with an estimated 1000 wintering across the state.

Sidebar: 10

A Field Guide to Desert Holes (2002), by Pinau Merlin, is a quirky look at underground critters most visitors usually won’t notice in the desert, unless you know where and how to look for them.

Sidebar: 11

Discover Utah's birds and the best places to spot them on the extensive www.utahbirds.org website. Includes photos, profile checklists and a log of rare sightings.

Sidebar: 12

In Desert Solitaire, Edward Abbey recounts how a gopher snake that lived beneath his trailer in Arches National Park seemed to keep the rattlesnakes away.

Sidebar: 13

Scientists have documented 16 native species of bats in Canyonlands National Park, accounting for nearly 90% of all bat species found in the entire state.

Sidebar: 14

Ancient bristlecone pines may be slow growing, but they’re believed to be the oldest living single organisms on earth, with some over 5000 years old.

Sidebar: 15

The common desert shrub nicknamed Mormon tea is a species of Ephedra plant, which Native Americans also used for medicinal purposes, including as a stimulating brew.

Sidebar: 16

Wildflowers of Zion National Park (1990), by Stanley Welsh, is an excellent pocket-sized guide that covers the most common wildflowers that hikers and visitors will encounter along the park’s trails, blooming from spring through fall.

Sidebar: 17

Wondering what flower you just saw? Use Arches National Park’s online flower database, searchable by month, color and name, or download free plant-finder keys from www.nps.gov/arch/learn/nature/wildflowers.htm.

Sidebar: 18

Take a sneak peek at Zion’s comprehensive plant library – a virtual botanical treasure chest for researchers and park rangers – online at www.nps.gov/zion/naturescience.

Conservation

Here under the desert stars and up by the devilish hoodoos, the dance of nature is profound, intricate and delicate. The uniquely adapted ecosystems are intimately tied to water, and even the smallest of environmental impacts can create huge change for one of North America's largest intact wildernesses. Top conservation challenges today are increased visitation, mining and resource extraction, land use and management, climate change, invasive species and man-made dams.

Land Use

Unfortunately, grazing, mining, oil and gas extraction, and military exercises still create scars around southern Utah’s parks and monuments. The debate on land use in Utah has become one of the largest hot-button environmental issues in the US West today.

Desert vegetation grows so slowly that even impacts left by early Western prospectors, ranchers and explorers may look fresh, and protected parklands remain damaged by long-ago visitors. Cows have had such a devastating impact on the desert that it no longer functions as the same ecosystem. Only on a few inaccessible mesa tops do fragments of ancestral plant communities survive. Today’s dry, brushy desert hardly resembles the landscape that existed even half a century ago, and it’s not likely to recover for centuries to come.

Plants that adapt best seem to be invasive weeds, which have quickly overtaken areas damaged by cows and human activities. Introduced plants such as tamarisk, Russian thistle (tumbleweed) and cheatgrass pose a serious problem, as they can force out native plants and animals, creating extensive monocultures. Cheatgrass even alters the chemistry of the soil, possibly rendering it unusable to other plants. And many invasive plants are nearly impossible to remove once they gain a foothold.

Construction of dams and reservoirs throughout the Southwest has radically changed the delicate balance that has sustained life here for millennia. In place of floodplains that once richly nourished riparian and aquatic food chains, dams now release only cold water in steady flows that favor introduced fish species and invasive weeds. In populated areas, the draining of underground aquifers is shrinking the water table and drying up desert springs and wetlands that animals have long depended on during the dry season.

A few darlings like reintroduced condors and bighorn sheep provide a glimmer of hope for the at-risk species found here.

Climate Change

The Environmental Protection Agency (EPA) estimates that temperatures in the US Southwest have risen by almost 2°F over the last century. Over the next 100 years, the NPS expects the Colorado Plateau will become hotter and more arid – a 2014 Bureau of Land Management (BLM) report said temps could rise by as much as 2˚ by 2060 – causing even more extreme droughts. This affects where plants grow, where animals eat, where wildfires burn, and even where people play. Across the Southwest, piñon pine are dying off at an alarming rate as a result of an ongoing drought, animals are changing habits to adapt to changing ecosystems, and the tourism industry is adjusting approaches as changing rain patterns affect river levels, sandstorms affect watersheds, and ski areas and even tourism seasons change as winter temperatures rise.

Cryptobiotic Crusts

One of the desert’s most fascinating features is also one of its least visible and most fragile. Only in recent decades have biological soil crusts begun to attract attention and concern. These living crusts cover and protect desert soils, gluing sand particles together so they don’t blow away.

Cyanobacteria, among the earth’s oldest living lifeforms, start the process by extending mucous-covered filaments that wind through the dry soil. Over time these filaments and the sand particles adhering to them form a thin crust that is colonized by microscopic algae, lichens, fungi and mosses. This crust absorbs huge amounts of rainwater, reducing runoff and minimizing erosion.

Unfortunately, this thin crust is instantly fragmented under the heavy impact of human footsteps, not to mention bicycle, motorcycle and car tires. Once broken, the crust can take up to 100 years to repair itself. In its absence, the wind and rains erode desert soils, and much of the water that would otherwise nourish desert plants is lost. Many of these soils formed during the wet climates of the Pleistocene and may be irreplaceable in today’s arid conditions. Tragically, as soon as the crust is broken and soil is lost, grasses will be permanently replaced by shrubs, whose roots fare better in the thinner soils.

Visitors to the Southwest bear a special responsibility to protect these living soil crusts by staying on established trails. Look closely before you walk anywhere – intact crusts form a rough glaze atop the soil, while fragmented crusts have sharp edges. At all costs, avoid walking or camping on these ancient soils.

Increased Visitation

Over 12.6 million people traveled to Utah's national parks and monuments in 2017 – that's a lot of boots on the ground, paddles in the water and wheels on the trail. And the five national parks are seeing an unprecedented spike in visitation. Zion leads the way, with a 70% increase in tourism since 2010, reaching 4.5 million visitors in 2017.

In a region where life hangs by a fragile thread, the heavy trampling of human feet and off-road vehicles leaves lasting impressions. Desert crusts, wet meadows and riverside campsites are slow to recover from such use, and repeated visits can cause permanent damage. The effects may accumulate so gradually they almost go unnoticed. Scientists at Bryce Canyon estimate that 3% of the vegetation disappears each year from people wandering off trail among the hoodoos – just tiny little bites that build up over time. Human remains like petroglyphs are also at risk from idiots leaving graffiti.

The park managers are acutely aware of this and actively try to mitigate visitor impacts wherever possible. Both Zion and Bryce Canyon have developed free public-transit systems and a growing network of pedestrian and bicycle trails as a way of reducing traffic congestion and air pollution. All of southern Utah’s parks and concessionaire businesses now encourage and facilitate recycling. Zion’s visitor center is a model of smart, sustainable ecobuilding practices that hopefully more national and state parks will imitate in the future, as much as their operating budgets allow.

Biological soil crusts are of particular concern, and all the parks have ‘Don’t Bust the Crust’ programs to educate visitors about their impact on desert soils.

But visiting national parks is good for the environment, right? Sure it is. More visitation means more visibility and awareness for protecting Utah's wild lands, it means an educated citizenry and it means more funds for the National Park Service (NPS).

If you want to minimize the impacts of your trip, consider riding bikes into the parks or at the very least carpooling, staying on trails, picking up litter and, of course, leaving no trace. The challenge of visitation is not just about air pollution and littering, it's also about noise pollution, light pollution that affects dark skies, and habitat encroachment.

Sidebar: 1

Lyrical and evocative of a beautifully sere landscape, The Secret Knowledge of Water: Discovering the Essence of the American Desert (2001), by Craig Childs, is required reading for anyone heading out into southern Utah’s backcountry wilds.

Sidebar: 2

Cadillac Desert: The American West and Its Disappearing Water (1993), by Marc Reisner, is an exhaustively researched, compelling account of the West’s most critical issue: balancing development with its most precious resource.

Sidebar: 3

To learn more about the great land debate, check out the Southern Utah Wilderness Alliance (www.suwa.org), a grassroots political organization that's been critical in the land-conservation fight.

Sidebar: 4

Edward Abbey is arguably Utah's most famous environmentalist. Check out The Monkey Wrench Gang (1975), a mostly fictionalized, raucous tale of ‘ecowarriors’ and their plan to blow up Glen Canyon Dam, along with the dreamy classic Desert Solitaire (1968).