{{Infobox_protected_area | name = Arches National Park
| iucn_category = II
| image = US_Locator_Blank.svg
| caption =
| locator_x = 70
| locator_y = 84
| location = [[Utah]], [[United States|USA]]
| nearest_city = [[Moab, Utah|Moab]]
| lat_degrees = 38
| lat_minutes = 41
| lat_seconds = 0
| lat_direction = N
| long_degrees = 109
| long_minutes = 34
| long_seconds = 0
| long_direction = W
| area = 76,358.98 acres<br><font size="-2">&nbsp; (76,193.01 federal)</font><br>309.01 km²
| established = [[April 12]], [[1929]], as a [[U.S. National Monument|National Monument]]
| visitation_num = 833,049
| visitation_year = 2006
| governing_body = [[National Park Service]]
}}
'''Arches National Park''' preserves over 2,000 [[natural arch|natural sandstone arches]], including the world-famous [[Delicate Arch]], in addition to a variety of unique geological resources and formations.

The park is located near [[Moab, Utah]], and is 119 square miles ([[1 E8 m²|309 km²]]) in size. Its highest elevation is 5,653 feet (1,723 m) at Elephant Butte and its lowest elevation is 4,085 feet (1,245 m) at the [[visitor center]]. Since 1970, 42 arches have toppled because of erosion. Arches National Park receives 10 inches (250 mm) of rain a year on average.

The area, administered by the [[National Park Service]], was originally designated as a [[U.S. National Monument|national monument]] on [[April 12]], [[1929]]. It was redesignated a [[U.S. National Park|national park]] on [[November 12]], [[1971]]. More than 833,000 people visited it in 2006.

==Features==

[[Image:Delicatearch.jpg|right|thumb|250px|Delicate Arch, one of the most famous arches in the park.]]
[[Image:WindowsArches ArchesNP.jpg|right|thumb|250px|North Window and South Window Arches]]
[[Image:Turret Arch 1.jpg|right|thumb|250px|Turret Arch]]
[[Image:Landscape arch 20030917 093317 1.1504x807.jpg|right|250px|thumb|Landscape Arch]]
[[Image:Arches 4 bg 012003.jpg|thumb|right|250px|Balanced Rock]]
Among the notable features of the park are:
* [[Delicate Arch]] — a lone-standing arch which has become a symbol of Utah
* [[Balanced Rock]] — a large balancing rock, the size of three school buses
* [[Double Arch]] — two arches, one on top of the other
* [[Landscape Arch]] — a very thin, very long arch over 300 feet (100 m); the largest in the park
* [[Fiery Furnace (park)|Fiery Furnace]] — an area of maze-like narrow passages and tall rock columns (see biblical reference [[Fiery Furnace]])
* [[Devil's Garden]] — with many arches and columns scattered along a ridge
* [[Dark Angel (park)|Dark Angel]] — a free-standing column of dark stone at the end of the Devil's Garden trail.
* [[Courthouse Towers]] — a collection of tall stone columns
* [[Petrified dunes]] — petrified remnants of [[sand dunes]] blown from the ancient lakes that covered the area.

==Geology==
The national park lies atop an underground salt bed, which is the main cause of the formation of the arches and spires, balanced rocks, [[sandstone]] fins, and eroded monoliths in the area. Thousands of feet thick in places, this salt bed was deposited over the [[Colorado Plateau]] some 300 million years ago when a sea flowed into the region and eventually evaporated. Over millions of years, the salt bed was covered with residue from floods and winds and the oceans that came in intervals. Much of this debris was compressed into rock. At one time this overlying earth may have been one mile thick.

Salt under pressure is unstable, and the [[salt bed]] below Arches was no match for the weight of this thick cover of rock. Under such pressure it shifted, buckled, liquefied, and repositioned itself, thrusting the Earth layers upward into domes. Whole sections dropped into cavities. In places they turned almost on edge. [[Geologic fault|Faults]] occurred. The result of one such 2,500-foot displacement, the [[Moab Fault]], is seen from the [[visitor]] center.

As this subsurface movement of [[salt]] shaped the Earth, surface erosion stripped away the younger rock layers. Except for isolated remnants, the major formations visible in the park today are the salmon-colored [[Entrada Sandstone]], in which most of the arches form, and the buff-colored [[Navajo Sandstone]]. These are visible in layer cake fashion throughout most of the park. Over time water seeped into the superficial cracks, joints, and folds of these layers. Ice formed in the fissures, expanding and putting pressure on surrounding rock, breaking off bits and pieces. Winds later cleaned out the loose particles. A series of free-standing fins remained. Wind and water attacked these fins until, in some, the cementing material gave way and chunks of rock tumbled out. Many damaged fins collapsed. Others, with the right degree of hardness and balance, survived despite their missing sections. These became the famous arches.

==History==
Humans have occupied the region since the last [[ice age]] 10,000 years ago. [[Fremont people]] and [[Ancient Pueblo People]] lived in the area up until about 700 years ago. Spanish missionaries encountered Ute and Paiute tribes in the area when they first came through in [[1775]], but the first European-Americans to attempt settlement in the area were the [[Mormon]] [[Elk Mountain Mission]] in [[1855]], who soon abandoned the area. Ranchers, farmers, and prospectors later settled Moab in the neighboring riverine valley in the 1880s. Word of the beauty in the surrounding [[rock formations]] spread beyond the settlement as a possible tourist destination.

The Arches area was first brought to the attention of the National Park Service by Frank A. Wadleigh, passenger traffic manager of the [[Denver and Rio Grande Western Railroad]]. Wadleigh, accompanied by railroad photographer George L. Beam, visited the area in September 1923 at the invitation of Alexander Ringhoffer, a [[Hungary|Hungarian]]-born [[Prospecting|prospector]] living in Salt Valley. Ringhoffer had written to the railroad in an effort to interest them in the tourist potential of a scenic area he had discovered the previous year with his two sons and a son-in-law, which he called the "Devil's Garden" (known today as the "Klondike Bluffs"). Wadleigh was impressed by what Ringhoffer showed him, and suggested to Park Service director Stephen T. Mather that the area be made a national monument.

The following year additional support for the monument idea came from Laurence M. Gould, a University of Michigan graduate student studying the geology of the nearby La Sal mountains, who was shown the scenic area by retired local physician Dr. J.W. "Doc" Williams.

[[Image:Fiery Furnace Panorama.jpg|left|thumb|400px|A panoramic view of sandstone fins of the Fiery Furnace.]]
[[Image:Tower of Babel ArchesNP UT USA.jpg|left|thumb|400px|A panoramic view of Tower of Babel.]]

A succession of government investigators examined the area, in part due to confusion as to the precise location. In the process the name "Devil's Garden" was transposed to an area on the opposite side of Salt Valley, and Ringhoffer's original discovery was omitted, while another area nearby, known locally as "The Windows", was included. Designation of the area as a national monument was supported by the Park Service from [[1926]], but was resisted by President [[Calvin Coolidge]]'s Interior Secretary. Finally in April [[1929]], shortly after his inauguration, President [[Herbert Hoover]] signed a presidential proclamation creating Arches National Monument, consisting of two comparatively small, disconnected sections. The purpose of the reservation under the 1906 [[Antiquities Act]] was to protect the arches, spires, balanced rocks, and other sandstone formations for their scientific and educational value. The name "Arches" was suggested by Frank Pinkely, superintendent of the Park Service's southwestern national monuments, following a visit to the Windows section in 1925.

In late [[1938]], President [[Franklin D. Roosevelt]] signed a proclamation which enlarged the Arches to protect additional scenic features and permit development of facilities to promote tourism. A small adjustment was made by President [[Dwight Eisenhower]] in [[1960]] to accommodate a new road alignment.

In early [[1969]], just before leaving office, President [[Lyndon B. Johnson]] signed a proclamation substantially enlarging the Arches. Two years later President [[Richard Nixon]] signed legislation enacted by Congress which significantly reduced the area of Arches, but changed its status to a National Park.

==Recreational activities==
Climbing of named arches within the park has long been banned by park regulations. However, following a successful [[free climbing|free climb]] of Delicate Arch by Dean Potter on [[May 6]], [[2006]], the wording of the regulations was deemed unenforceable by the park [[attorney]]. In response, on [[May 9]], [[2006]], the park revised its regulations as follows:

:"All rock climbing or similar activities on any arch or natural bridge named on the [[United States Geological Survey]] 7.5 minute topographical maps covering Arches National Park are prohibited."<ref>{{cite web| url=http://www.sltrib.com/utah/ci_3804296| title=Park tweaks rules after Delicate Arch climb| author=Lisa J. Church, Salt Lake Tribune| accessmonthday=May 10 | accessyear=2006| }}</ref>

Climbing of other features in the park is allowed, but regulated. The revised regulations also prohibit [[slacklining]] parkwide. Approved recreational activities include auto touring, backpacking, biking, camping, and hiking, some of which require permits. There are also guided commercial tours and ranger programs.

==Publicity==
American writer [[Edward Abbey]] was a [[park ranger]] at Arches National Monument where he kept journals that became his book ''[[Desert Solitaire]]''. The success of this book, as well as the rise in [[adventure tourism|adventure-based recreation]], has drawn many [[hikers]], [[mountain bike|mountain-bikers]], and [[off-road]] enthusiasts to the area, but activities are limited within park boundaries: camping, foot hiking (along designated trails), and driving only along marked roads.

The opening scenes of the movie ''[[Indiana Jones and the Last Crusade]]'' were filmed at the park.

==Biology==
[[Image:Collard lizard.jpg|250px|thumb|right|The Western Collard Lizard]]There is an abundance of [[wildlife]] in Arches NP. The list includes: [[Spadefoot Toad]], [[Scrub Jay]], [[peregrine falcon]], many kinds of [[Sparrows]], [[Red Fox]], [[Desert Bighorn Sheep]], [[Kangaroo rat]], [[Mule Deer]], [[mountain lion]], [[Midget-Faded Rattlesnake]], [[Yucca Moth]], many types of [[Cyanobacteria]], [[western rattlesnake]], and the [[Western Collard Lizard]].

Plants also dominate the landscape in the park. The list of plants consistes of: [[Prickly pear cactus]], [[Indian RiceGrass]], [[Bunch Grasses]], [[Cheatgrass]], [[Lichen]], [[Mosses]], [[Liverworts]], [[Utah Juniper]], [[Morman Tea]], [[Blackbrush]], [[Cliffrose]], [[Four-winged Saltbrush]], [[Pinyon pine]], [[Stemless woollybase]], [[evening primrose]], [[sand verbena]], [[yucca]], and the [[Sacred Datura]].

==Photo Gallery==
<Gallery>
Image:Rocks ArchesNP Moab UT USA.JPG|Fin Canyon in Devils Garden
Image:Sandstone Landscape.jpg|Landscape behind Delicate Arch
Image:Devils Garden.jpg|Sand Dune Arch Fins
</Gallery>

==References==
* ''The National Parks: Index 2001–2003''. Washington: [[United States Department of the Interior|U.S. Department of the Interior]].
<references />

==External links==

{{Commons|Arches National Park|Arches National Park}}
* [http://www.nps.gov/arch/index.htm Arches National Park Official site]
* {{Wikitravel}}
* [http://www.outdoorzen.org/site/beta/moab/ Arches Canyoneering and Hiking Information]

{{National parks of the United States}}
{{UT Parks}}
{{Utah}}

[[Category:1971 establishments]]
[[Category:Colorado Plateau]]
[[Category:Grand County, Utah]]
[[Category:National parks in Utah]]
[[Category:National parks of the United States]]
[[Category:Natural arches of Utah]]

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