Rock formations shaped by geological forces and erosion feature heavily in this state's red-hued national parks.
As the USA's National Park Service celebrates its centenary, we're profiling the wilderness areas it manages.
Today: The national parks of Utah . . .
Bryce Canyon National Park
"One of the world's best sites for an appreciation of the inexorable, titanic forces which have shaped the globe's surface."
- Nicholas Scrattish, historian, in 'Historic Resource Study Bryce Canyon National Park'
This landscape is actually a collection of natural amphitheatres — stone bowls — rather than canyons. Bryce Amphitheatre covers 15.5 square kilometres.
Inside the hollows are hoodoos, which are tall spires of rock protruding from the bottom of arid basins. The park has more hoodoos than any other spot on Earth.
Visitors gazing at hoodoos from the basin rim or trails below see stoic, sometimes human-shaped rock forms ranging from as tall as adults to taller than 10-storey buildings. Observing the upright shapes gives a sense of being a spectator in a Greek amphitheatre. It's understandable why Paiute inhabitants here said the hoodoos were "Evil Legend People".
The dramatic figures of Bryce were shaped by water's freeze-thaw cycle and by erosion from rain (as opposed to by a river carving a canyon). And they continue to be eroded.
Here, about 434km from Las Vegas and Salt Lake City, this landscape can be seen by car or on foot, as well as on snowshoes or cross-country skis and by winter backpacking.
This park is named for homesteader Ebenezer Bryce, a Scottish immigrant who arrived in 1875 and reputedly once said, "It's a hell of a place to lose a cow."
A less practical take on this land today includes such annual events as Prairie Dog Day and geology and astronomy festivals. And because park visitors aren't tending cattle like Mr Bryce, they can stop to appreciate the colours of the rock, which are said to be especially vibrant after a rainstorm.
Size: 35,835 acres
Founded: National monument, 1923; national park, 1928
Attendance: 1,745,804 (2015)
Arches National Park
"You can't see anything from a car . . . walk, better yet crawl, on hands and knees, over the sandstone and through the thornbush and cactus.
When traces of blood begin to mark your trail you'll see something, maybe."
- Former Park Service employee Edward Abbey, in his introduction to 'Desert Solitaire: A Season in the Wilderness', on how best to experience the park
It's no surprise the US Postal Service chose to depict this park on one of its commemorative Park Service centennial stamps. Cameras love the complementary combination of red-orange sandstone against high-desert blue skies. Photographers flock here, 236 miles from Salt Lake City, to capture the 2000 arches, as well as the fins, balanced rocks, pinnacles and spires in their best light. It's alluring to filmmakers, as well. Indiana Jones and the Last Crusade is among the movies with scenes filmed here.
The story of the arches begins 65 million years ago, when the area was a dry seabed and the rock was still uncarved, raw material.
Because the resulting natural beauty draws crowds, the Park Service suggests visiting before 8am or after 3pm. And they advise treading with care. The formations are more delicate than their rocky foundation would suggest. That's also true of the ground.
Visitors should avoid stepping on the crusty cryptobiotic soil, which is alive and prevents erosion. That said, seeing the park on foot is suggested and hiking options — from family friendly to strenuous — are plentiful. Among the more physical hikes is a ranger-guided, three-hour one to Fiery Furnace, which includes rock scrambling up and through narrow cracks and along steep ledges above drop-offs.
Sightseeing by car is also possible; popular features, such as Balanced Rock, are visible from the main road.
In this park, so dominated by stony beauty, wildflowers may get overlooked. The Park Service provides an interactive wildflower guide to help visitors to determine what they'll see and when.
Size: 76,679 acres
Founded: National monument, 1929; national park, 1971
Attendance: 1,399,247 (2015)
Canyonlands National Park
"Some of the most remote and rugged terrain in the continental United States."
- NASA, on its Earth Observatory website
At this landscape in southeastern Utah near Moab, the rock art (petroglyphs and pictographs) in the Great Gallery is a sort of a message in a bottle sent centuries ago. The well-preserved, life-sized figures with intricate designs are hailed as the most significant rock art in North America.
As the human parade crisscrossing this region evolved, European explorers found Canyonlands to be more of an impediment than a destination.
Today, this land may be appreciated in as little as an hour, with a drive to Grand View Point for a panoramic vista. Add another hour, and there's also time for an 800m hike to Mesa Arch, one of the most popular sites here.
Canyonlands' geographic districts include Island in the Sky and the Needles district. Island in the Sky is a mesa on sheer sandstone cliffs with spectacular views. The Needles district offers variegated spires of cedar mesa sandstone. Activities include hiking and four-wheeling. Kayaking on calm stretches of the Green and Colorado rivers provides another perspective.
The Maze district ranks among the most remote areas in the United States. Backpacker Magazine included the Maze on its 'America's 10 Most Dangerous Hikes' list, noting that route-finding is tough among "sandstone fins and interconnecting canyons that all seem to look the same".
It's no wonder outlaws, including Butch Cassidy, made use of Horseshoe Canyon in the late 1800s, taking refuge in the confusing network of canyons.
Size: 337,598 acres
Attendance: 634,607 (2015)
Capitol Reef National Park
"With abundant evidence of an ancient culture, as well as artifacts and orchards from a more recent frontier community, the park offers fascinating human stories that interweave with its natural history."
- Rick Stinchfield, author, in 'Capitol Reef National Park: The Complete Hiking and Touring Guide'
This remote landscape is a wrinkle in time. Its main feature, the Waterpocket Fold, is a ripple in the Earth's crust known as a monocline. Here, the folding and tilting of rock layers opened a glimpse into millions of years of geologic history.
The park gets its name from white domes of Navajo sandstone that resemble capitol domes and rocky cliffs that form a land barrier reef. Such features earned the park a place on the Wilderness Society's 'America's best kept secrets' list. At night, its starry status as a Dark Sky Park is revealed.
This craggy topography, 56km from Salt Lake City, attracts rock climbers. Hiking (day and backcountry) and car tourism also afford ample views. Various walking trails may lead into a narrow gorge, to cliff tops, under a stone arch or to historic inscriptions. Road routes are paved and unpaved. (Rustic roads require four-wheel-drive vehicles.)
Despite the rocky terrain, this area has an agricultural past.
Fremont and ancestral Pueblo people added farming to their hunter-gatherer ways about 2000 years ago, growing corn, beans and squash. Petroglyph panels throughout the park depict stories of the early inhabitants.
Today, there are no restaurants or lodging here. However, an oasis of hospitality exists at the Gifford Homestead (a farmhouse on the National Register of Historic Places). Now a museum and store, it sells reproduction household tools, jellies, rag dolls and books. Also popular: locally made fruit pies.
Size: 241,904 acres
Founded: National monument, 1937; national park, 1971
Attendance: 941,029 (2015)
Zion National Park
"Never before has such a naked mountain of rock entered into our minds! Without a shred of disguise, its transcendent form rises preeminent. There is almost nothing to compare to it."
- Frederick S. Dellenbaugh, early explorer-topographer of the American West
Americans look anything but sedentary here among the formations of sedimentary rock. The terrain invites climbing, scrambling, hiking, wading and canyoneering. Although shuttle buses and cars can access views, sightseeing here can seem a bit like a competitive sport.
Among the challenges is the Subway, a slot canyon that requires route finding, rappelling and swimming. (Permits are required.)
Lower-exertion paths are also available among the trails that meander throughout the varied landscape of desert, mountains, forests, valleys and river.
The Narrows, a canyon-network trek along the Virgin River that involves wading and, sometimes, swimming, is less challenging. The visual reward for such efforts is evident in this: Zion is one of the most Instagrammed places in the country. (Scenes in the Oscar-winning 1969 film Butch Cassidy and the Sundance Kid were filmed here.)
Spectacular sites include a man-made addition. As the US Interior Department puts it, "Zion is home to one of the greatest engineering feats of modern times."
To make the area accessible, construction began on a 40km stretch of road to connect Zion to the Grand Canyon and Bryce Canyon. The Zion-Mt Carmel Highway and Tunnel, completed in 1930, includes a 1.7km-long tunnel that slices through Zion's sandstone cliffs. The tunnel has windows to provide views of Zion Canyon.
Early inhabitants called this land Mukuntuweap, meaning straight canyon in the language of the Southern Paiute. Zion is the Mormon name. Other names here include the Great White Throne (of white Navajo sandstone), the Watchman, Three Patriarchs, Weeping Rock, Checkerboard Mesa, Emerald Pools.
Monkey flowers and hanging gardens (created by water seeping from sandstone and feeding ferns and mosses) are part of a diversity that's made possible by the park's location at the intersection of the Colorado Plateau, Basin and Range Province and Mojave Desert.
This park is open all year, and fans of snowshoeing and cross-country skiing flock to Zion in winter.
Size: 147,237 acres
Founded: As Mukuntuweap National Monument, 1909; as Zion National Park, 1919
Attendance: 3,648,846 (2015)