Location/Geography: Grand County, Moab, eastern Utah. Area: 76,358.98 acres; 119 square miles.
Spotlight: This park setting has more arches than any other place on the planet! Ancient salt evaporates is what eventually gave way to a wondrous and tilted topography featuring sandstone marvels. Delicate Arch is the most famous icon in park’s listing but it’s quite a jaunt to get there. Hot, dry summers and temperate winters usually free of snowfall accumulations––that’s Arches NP. Ideal year-round park to visit. Focus: geology, flora and fauna, and human history (from the primal to the contemporary).
Snapshot: Arches NP’s landscape boasts meticulous geologic formations, mostly a template of eloquent arches. The blueprint and formula necessary to create an arch requires a set number of rules nature has to follow: the right materials, in this case sandstone works best, erosion by wind, location of the arch, and timing. Try millions of years! While the park’s numerous spires, balanced rocks, eroded monoliths and fins are impressive enough, the number of arches here is nothing less than incredible. In fact, the park’s namesake is given for a veritable Parthenon of such phenomena on a grand scale, boasting over 2,000 of these natural sandstone wonders. A prime example of an arch is one of the most famous on the planet, Landscape Arch. With its 290-foot span, to behold this monstrosity of grace is indeed one of those very special ooo-ahhhh moments. Even smaller arches give pause for meditation. To qualify as an arch, a 3-foot eyelet is the minimum measure for an opening to be officially classified as an arch. The assemblage of arches small and large found throughout the park is nothing less than sensational. Some can seen from the road, others near a short, easy pathway, and still others that entail a bit more aggressive hiking. The park's highest elevation is 5,653 feet at Elephant Butte. The lowest elevation is 4,085 feet also at the Visitor Center. Since 1970, an amazing 43 arches have toppled because of erosion. Originally designated as a national monument in 1929, in 1971 the setting was later deemed a national park. Incidentally, Arches NP features one of the best Visitor Centers in the park system and tourists are encouraged to see its many informative displays and check out the many facets of the park before continuing with their visit.
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The high road leading up to Arches NP and then going down into its capacious valley-like setting is suspenseful in a surprising sense. At first, towering walls of sandstone rise and form a protective barrier leading into the park, with the prominent 2,500-foot displacement of the Moab Fault cutting through this sector. Then comes the drop and Nature's stage offering a variety of arches fashioned in exotic shapes and sizes. Balanced rocks, meticulously hewn figures, and the dramatic rise of the La Sal Mountains in the background tell the visitor there is something wonderful and singular in this setting. The suggestive names on the map also confirms this fact: The Devil's Garden, The Fiery Furnace, and Courthouse Towers, to mention only some.
Guided Tour Essentials: Remarkably, none of these majestic landmarks would be here were it not for salt. That’s right: ordinary salt has something important to do with this region’s unparalleled sculpturing of such creations. For instance, the physical environment (a/k/a/"physiographic") here amounts to layers of sandstone formations (stratified) shaped into alternate ridges (corrugated), in which the strata slopes downward (anticline). In fact, there are several northwest-trending strata seen here, which explains the rather noticeable tilt of the landscape. Arches NP is a high altitude desert landscape, whose lowest elevation is 4,085 feet (at the Visitor Center). Thus some visitors tend to feel the rarefied air more than others. For those having difficult with breathing, park rangers suggest taking time to acclimate and avoiding rushing about when seeing the sights.
From the point of a geologist the park is essentially a sprawling physiographic environment of anticlines, with the oldest beds the bottom of the strata pile (the core). Naturally, anytime there is a major fold in the planet’s crust it requires an immense geophysical force. Here that force amounts to an anticline, which was caused by a slow and gradual uplift assisted by a consequential movement of salt. In short, the weight of many sandstone layers were laid over an ancient salt bed. The weight of the layers exerted pressure and eventually evaporated material (salt) beneath the pile liquified, then thrust upward through these multiple layers of sandstone. In time, the process created structural salt domes. These in turn formed the more singular salt anticlines: a convex fold of exquisite fold of rock layers. The net result has created spacious valleys resulting from an eventual and major collapse. The Salt Valley and Cache Valley anticlines in the park are prime examples. Both sectors are commonly tilted, revealing irregular masses of rocks much younger than those seen on the valley's walls. This occurrence suggests they were initially produced by a colossal collapse millions of years ago. It’s quite amazing to think ordinary salt was responsible for the majesty we see and admire today in this sandstone haven spread out below the towering backdrop of the La Sal Mountains. Of course, there’s more to the blueprint of nature that makes Arches NP what it is. For instance, faulting. Entire sections of rock have subsided into pavement tracts between the salt domes, and in places are turned almost on edge. Faults create some of nature’s most awesome offset land features. At the Visitor Center, which is a recommended stopover before entering the park, the Moab Fault is plainly visible. Its huge displacement measures 2,500 feet!
The Crucial Role Of Salt Associated With Geology: A summary of what created the park's vivid rock formations comes down to these aforementioned base materials, all denoting a precise process of geologic events and transformation. The right materials initially set the stage. Namely, a major and primal inland evaporate of salt, gypsum and potash originally deposited by super-saline sea water. This aquatic event supplied the ideal materials and environment for a future landform setting of fastidious fabrication. When the various constituents were deeply buried, this is when the evaporate minerals turned plastic. Like putty, the minerals flowed (underground), eventually squeezing upward under enormous pressure. Finally, over time the material hardened. Only then could the process of chemical and weathering erosion go to work. Millions of years later arches formed. These erosional masterpieces of nature’s doing are evidenced by massively thick sandstone layers with abundant parallel vertical joints.
(Note: Unlike faults, joints do not show any relative movement, but only telltale fractures in the rock.) Joints are caused by natural bending across the anticlines, thus defining the shape and contour of the landscape.
Less dense, and much more buoyant than overlying sedimentary rocks, salt and gypsum really had nowhere to go other than to well upward. In this step of the process, there was enough exerted pressure to arch overlying rocks into a series of anticlines. The trend of these great folds was a northwest-to-southeast orientation matching ancient fault lines. Eventually, most of the salt was dissolved. Only gypsum remains in the cores of the anticlines.
Due to Arches NP exquisite geologic background its topographical setting is likely one of the most bizarre and appealing top draw attraction in the Southwest.
What Makes An Arch? Before discussing the geologic essentials of Arches NP, the nature of an arch needs explaining.
Often these engaging oddities of Nature are mistaken for a natural window, yet they're really not the same. Similarly, arches are not natural bridges. Although both are geologic formations involving sedimentary rocks usually made from sandstone, an arch is formed in a narrow ridge walled by cliffs. The arch itself is formed by erosion, where a softer rock stratum beneath cliff-forming layers gradually erodes out to the point a freestanding arched span remains. Arches commonly form where cliffs are prone to erosion, usually honed by wind. In this region, however, rivers and streams provide ideal and natural weathering processes. To fashion an arch, elements of erosion go to work on inherent weaknesses in rocks, making them weaker until their solid foundations are breached. As a persistent process of erosion, it follows from a small opening to a gargantuan aperture how arch is born and continues to form over the eons. Now you know what an arch is and how they are formed. . .like this:
And how about a pair of spectacles for a design?
What Are Natural Bridges By Comparison? These equally fascinating products of nature signify a subtype of an arch that are primarily water formed. The precise distinction between a bridge and arch is also somewhat whimsical. Since these phenomena are formed by water, usually a stream, a natural bridge is (by some definitions) considered a natural arch spanning a valley of erosion. It follows the operative word here is "spans," entailing a valley (or an arroyo to be more precise). In contrast, arches are natural events worn away by something other than running water, where wind is usually the erosive agent. Compare an arch to a natural bridge such as Rainbow Bridge (Lake Powell country and directly standing below the black bulge of Navajo Mountain). This engaging monstrosity of sandstone is caused by water flowing through the formation; at least to the point where a bridge of such magnitude eventually formed. However, at Arches NP, water worked in an entirely a different way. It first seeped into the surface cracks of the Navajo and Entrada Sandstone formations, as well as into joints and folds, thereby accounting for these principle layers. Then ice during the winter months also formed in the fissures. The ice expanded and exerted pressure on surrounding rock that later broke off in fragments. Winds then removed the loose particles. Eventually, a series of freestanding fins remained. Wind and water continue the process. In some formations, the cementing material of fins gives way and chunks of rock tumble out. Many of these damaged fins also collapse. Others, however, and with the right degree of hardness and balance, survive despite their missing sections. This meticulous and relentless sculpturing is a perpetual process. As for natural bridges, such equally striking rarities form when a watercourse eventually breaks through solid rock. At that time, erosion takes over, much the same as with an arch.
Here is a notable example of a natural bridge (Natural Bridges National Monument's, Owachomo):
Geology Essentials: The park provides an ideal geologic topography for its profusion of scenic attractions, including a maze of mini canyons carved between tall, thin fins of sandstone. Of course, differential erosion is at work here, where hard and relatively softer rocks are aligned (as layers) in an ideal matchup thereby preserving select features. For instance, this captivating image of the park's renown Three Gossips:
All the spellbinding features that Arches NP is famous for is primarily due to ideal foundational materials––natural shaping forces of erosion over the eons––and of course timing and uplift (of the entirety of the Colorado Plateau (likely between 70 and 30 million years ago). What is seen today (as a petrified sand flooring) began as a vast inland sea that flowed into this region, then eventually evaporated. A residue salt bed remained. Deposited in the massively thick Paradox Basin of the Colorado Plateau some 300 million years ago, the salt bed was eventually covered with debris eroded from the Uncompahgre Uplift (a/k/a/ the "Ancestral Rockies") to the northeast. During the Early Jurassic Period of the Mesozoic Era (210 million years ago), an arid climate prevailed throughout the region. Later, Navajo Sandstone was deposited, and eventually followed by an added sequence of stream and windblown sediments known as the Entrada Sandstone (140 million years ago). In time, over 5,000 feet of younger sediments were deposited overtop the original base foundation, which has long since eroded (well, for the most part eroded). Remnants of its pavement still remain, including exposures of the Mancos Shale from the Cretaceous Period of the Mesozoic Era (145 million years ago). Combined, all this depositional material created a multitude of arches in varying shapes and sizes, mostly honed from Entrada Sandstone.
Bonus Details: It's the original evaporite material of the earlier deposits laid down that really makes Arches NP what it is today. Indeed, the weight of this immense sandstone surface area throughout the region is what caused the salt bed below it to virtually liquefy, from which all else followed. These occurrences represent a type of structural dome formed from a thick bed of evaporite minerals (mainly salt or halite) at a greater depth. It’s this unique domed landscape that vertically penetrated into a surrounding rock strata. The process results in a diapir, which is a type of intrusion where a more mobile material is forced into brittle overlying rocks. Today, flowing water throughout this territory is as rare as a natural rose bush. Yet the evaporated salt that played such an important role in what we see today is what formed these great domes. Salt was also initially deposited with marine basins of saline water. When water flows into a basin, the accumulation is confined at some point and evaporation eventually occurs. This process results in the precipitation of salts from the solution, and in turn deposits evaporates. Were it not for these evaporates there would be no national park called “Arches.” As it turns out, the evaporates provide the key to the eloquent geology since it was the subsurface movement of salt that helped shape today’s much admired landscape. Later, and once the upwelling occurred, elements of erosion removed the younger rock layers from the surface revealing the gallery of arches and other marvels. All this visual enjoyment is due to evaporated salt and meticulous erosion.
Can you imagine this terrain without such embellished sandstone features?
Or this. . .the most iconic of arches in the national park?
The Ancestral Rocky Mountains: Because the Uncompahgre Uplift plays a vital role in Arches NP's landscape, some background about this geophysical force is key to understanding why this ancient range of mountains is so important to understand. Eroded away millions of years ago, the uplift of this ancient range must be seen from interpreting the existing basin stratigraphy, namely the unconformities (missing rock formations) and variable sedimentation rates. Many of its structures in Colorado and New Mexico were altered by later deformation during the celebrated so-called Laramide Orogeny (marking a lengthy period of intense mountain-building in western North America that began 70 to 80 million years ago and ended some 35 to 55 million years ago.). At the same time, there was the formation of the Rio Grande Rift in central New Mexico. Both events further complicate identification and interpretation. That’s because mountain-building episodes and rifting destroys or alters the geologic record. However, we do know the Ancestral Rockies were created, then later raised close to the present-day formation of the Rocky Mountains. The deformation of the original basement landscape happened as a result of the earlier range. We also know that during the late Paleozoic Era, perhaps some 240 to 250 million years ago, North America was much closer to the equator (due to the continual migration of all tectonic plates). Regional elevations closer to the Ancestral Rockies were also much closer to sea level. The key to the aftermath of these combined events is the uplifting of the Colorado Plateau province, which happened sometime between 70 and 40 million years ago, a fairly recent geologic event. What we don’t know about this great uplifting caused by tectonic plate subduction is whether it happened all at once, or in several pulses. Geologists usually think the latter.
This map depicts the original landscape of the Rockies:
While this picture depicts the second rising of the Rocky Mountains fronted by the aptly named Uncompahgre National Forest (in southwestern Colorado):
From Rocks To Riches: Why is land and material deformation in this region so important, specifically relating to the Ancestral Rockies? The answer: vast oil and gas reserves! Areas thus deformed by this ancient range have been, and will continue to be, one of the most economically productive regions in North America. Because this major uplift created structures that have yielded astonishing deposits of oil and gas, geologists, especially those in the petroleum industry, fawn over this type of terrain. Indeed, the western United States continues to be poked and prodded for exploration. Basins, such as the Moab region which trapped sediment and eventually eroded off the Ancestral Rocky Mountain uplifts, also girdled the biochemical catalysts for hydrocarbon creation. It’s also the folded and faulted nature of this range that has created an ideal locale for hydrocarbon accumulation. Prodigious amounts of evaporates that domed upwards through time, then formed excellent traps for oil and gas, are the coveted prize. Moreover, mechanisms of ancient deformation may determine where oil and gas are presently trapped. Although the Ancestral Rockies no longer dominate the skyline, the deformation of the today’s landscape has contributed to an ongoing hankering and dependence on fossil fuel sources by the oil and gas industries. On this note, we can also be thankful for our national parks and monuments that help save off rapacious quests to locate such energy resources.
Given what the penchant of the fossil fuel industry this picture kinda says it all, don't you think?
Human History: Humans have occupied this region since the last ice age, approximately 110,000 to 10,000 years ago. Human habitation also began 10,000 to 12,000 years ago, which marks the Pleistocene Period (an epoch extending from 2.5 million to 12,000 years, and possibly later). Both the Fremont people and prehistoric dwellers, the Ancestral Puebloans, lived in the region until some 700 years ago.
Later, Spanish missionaries met with Ute and Southern Paiute tribes in the area (about 1775). The missionaries represent the second camino de entrada (literally, the route of entry) into the Southwest after Coronado's conquistadors first came to the Southwest in 1540. The first European-Americans to attempt settling here are attributed to the Mormon Elk Mountain Mission in 1855. Settlement, however, was soon abandoned as the church congregation ventured farther south to Bluff and Blanding, among other places scattered throughout Utah and Arizona. Eventually, ranchers, farmers and prospectors wandered into the seeming desolate desert region. They, too, took their chances settling in and around Biblically-named Moab in the 1880s. Although encampment was never easy, the imposing backdrop of the La Sal Mountains and inspiring view of what later became Arches NP must have encouraged these new arrivals to stay. Perhaps the most famous modern day person who lived and worked here for a time was Edward Abbey. His epic eco-bible tome, Desert Solitaire, was written and inspired by the setting when he was employed as a ranger at the (then) national monument. I highly recommend reading this engaging tome and take on Abbey's pointed views about standing up for the environment (which he surely did. . .and sometimes with a scathing remarks intended for those who felt differently on the matter).
The thing about this long since deceased eco warrior is that he continues to inspire others based on his staunch pro environmental writings. Some think of Abbey as a curmudgeon, while others figure he is an environmental gadfly. Whatever. He, of course, wasn't one to feel sensitive about epithets attached to his name or his cause chiefly based on a closed-door policy to all industry. It would be a shame not to read this revealing tome, Solitaire, before or after visiting Arches NP.
Flora And Fauna: Even in such a desert-canyon setting with its imposing mountainous backdrop there's an abundance of wildlife, avians and plants to see. As a biome, which is climatically and geographically defined as similar climatic conditions that characterize communities of plants, animals and soil organisms (often referred to as ecosystems), this entire setting is filled with a diversity of life forms. Among the numerous critters and avians are red fox, desert bighorn sheep, mule deer, bobcats and mountain lions. Peregrine falcons are the faster-flying avians in the disparate company of red-tail hawks and other raptors. Vipers and non-venomous snakes, along with a variety of lizards, are just as common. Plants include typical high desert geniuses such as cactus, joint-fir (a/k/a/ "Mormon" or "Navajo Tea"), cliffrose, junipers and piñon pine, evening primrose, sand verbena, yucca and the so-called sacred datura (a/k/a/ "thornapple" or "jimsonweed"). Just so you know what to look for here's what this common plant looks like:
The fragile black-bluish cyanobacteria is also prevalent. Visitors should refrain from walking on this spongy-looking clumped mass since its living colony helps stabilize the soil and takes hundreds of years to become established. Here's what a patch of this crusty-looking topping looks like and always avoid walking on this life form:
Prominent Vistas: The biggest scenic attractions at Arches NP are, of course, the array of arches. The most popular are Delicate and Landscape arches. Courthouse Towers, The Tower of Babel, The Organ, Devils Garden and Fiery Furnace, and Balanced Rock also compete for one’s attention. Of course, with thousands of arches, fins and monoliths to gaze at, the only dilemma most visitors have to wonder or worry about is what to see and how much time they have to see it. A network of paved roads and trails, some of them unpaved, leads the way. The recommendation is to allow plenty of time to explore and relish the view of this monumental national park. Feast your eyes on these scenes and tell me you're not seeing the absolute best of Nature's awesome designs, as well as a place where there are more arches than anywhere else on the problem (which is a true statement). . .
And just to give you an idea of perspective, checkout this view of the aptly named Double Arch:
Recommended Hikes: Considered moderate by most hikers, Delicate Arch is 3 miles roundtrip. What's waiting to be seen at the end of the trail is what some hikers consider the added bonus. Arguably, the next best hike is Devil's Garden to Double-O Arch: 4 miles roundtrip, the longest of the maintained trails in the park. The trail passes nearly a dozen arches, offering excellent views of the La Sal Mountains, Salt Valley and scores of fins. The nearby path leading to Landscape Arch is fairly easy but is somewhat steeper and rockier beyond. There's also a slightly longer trail route (5 miles), the roundtrip to Double-O Arch that returns by way of the primitive loop trail, passing the majestic Fin Canyon.
This iconic landmark, of course, denotes Arches most famous and often visited backcountry attraction: Delicate Arch.
A Word Of Caution: Hiking in warm-to-hot weather always entails common sense rules of desert-country hiking. Ergo, water is the vital elixir when in the desert and should be carried at all times. Wearing a hat, sunglasses and sunblock is also highly recommended. Hiking poles is always a good option.
Other Recommended Hikes: Park Avenue (1-mile) and its Courthouse Towers sector; The Windows (1-mile roundtrip), which is near Balanced Rock and leads to Double Arch, Turret Arch and the North and South Windows; also, The Fiery Furnace (2 miles).
Other hikes range from easy to strenuous, some escorted by rangers. These are the more informative, though slower, hikes, but are very enjoyable regarding the learning along the way.
Directions: To Moab, Utah, drive south of I-70 on Hwy. 191 26 miles (41.8 km). From Kayenta, Arizona, take Hwy. 163, then at Bluff take Hwy. 191 (134 miles/215 km). Arches NP is just north of town.
Contact Information: Arches National Park, P. O. Box 907, Moab UT 84532-0907. Phone (visitor information): 435-719.2299. Fax 719.2300. Email embedded in NPS site's URL (click on "Email Us")
Here’s some parting shots to enhances your memories (and maybe entice you to come see for yourself the beauty and atmosphere of this compelling landscape). . .
And so, DKos community, we come to the end of another trail, another armchair tour or special supplement. There will be other scenic places to tour and more supplemental topics to read and think about, so stay tuned for a continuation in this series.
As always, your thoughtful commentaries are welcomed.
P. S. For a list of all previously published diaries, and there are quite a lot of them, these URL’s can be found by tapping into my profile. The list is long and will require hitting “Next” at the bottom of each list. To mention only some of the places and topics on the list. . .Arches, Canyonlands, Bryce and Zion national parks; Monument Valley; Chaco Canyon, Glen Canyon, Glen Canyon-Lake Powell, Desert Ecology, Ethnobotany, the Colorado Plateau, Ancestral Puebloan and Puebloan human history, Archeoastronomy, Res Dogs, and some few others. Lots more topics and landmarks, including off the Colorado Plateau, are forthcoming. Thank you for supporting these ongoing diaries. If you desire leaving a comment on these missive postings, please contact me either through my profile’s email or directly to the diary itself. I try to make a sweep of all the diaries, for comments, at least once and maybe twice a week. In other words, if asking a question or addressing a thought that requires same, I will be delighted to respond.