Canyonlands National Park

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Canyonlands National Park
IUCN category II (national park)
CanyonlandsNP GreenRiverOverlook.jpg
Looking over the Green River from Island in the Sky
Map showing the location of Canyonlands National Park
Map showing the location of Canyonlands National Park
Location San Juan, Wayne, Garfield, and Grand counties, Utah, United States
Nearest city Moab, Utah
Coordinates Lua error in package.lua at line 80: module 'strict' not found.
Area 337,598 acres (527.497 sq mi; 136,621 ha; 1,366.21 km2)[1]
Established September 12, 1964 (1964-09-12)
Visitors 542,431 (in 2014)[2]
Governing body National Park Service

Canyonlands National Park is a U.S. National Park located in southeastern Utah near the town of Moab. It preserves a colorful landscape eroded into countless canyons, mesas, and buttes by the Colorado River, the Green River, and their respective tributaries. Legislation creating the park was signed into law by President Lyndon Johnson on September 12, 1964.[3]

The park is divided into four districts: the Island in the Sky, the Needles, the Maze, and the rivers themselves. While these areas share a primitive desert atmosphere, each retains its own character. Two large river canyons are carved into the Colorado Plateau by the Colorado River and Green River.[4] Author Edward Abbey, a frequent visitor, described the Canyonlands as "the most weird, wonderful, magical place on earth—there is nothing else like it anywhere."[5]

Recreation

Canyonlands is a popular recreational destination. On average 440,039 people visit the park each year.[2] The geography of the park is well suited to a number of different recreational uses. Hikers, mountain bikers, backpackers, and four-wheelers all enjoy traveling the rugged, remote trails within the Park.

Rafters and kayakers float the calm stretches of the Green River and Colorado River above the Confluence. Below the Confluence, Cataract Canyon contains powerful whitewater rapids, similar to those found in the Grand Canyon. However, since there is no large impoundment on the Colorado River above Canyonlands National Park, river flow through the Confluence is determined by snowmelt, not management. As a result, and in combination with Cataract Canyon's unique graben geology, this stretch of river offers the largest whitewater in North America in heavy snow years.

The Island in the Sky district, with its proximity to the Moab, Utah area, attracts the majority (59 percent) of park users. The Needles district is the second most visited, drawing 35 percent of visitors. The rivers within the park and the remote Maze district each only account for 3 percent of park visitation.[6]

Political compromise at the time of the park's creation limited the protected area to an arbitrary portion of the Canyonlands basin. Conservationists hope to complete the park by bringing the boundaries up to the high sandstone rims that form the natural border of the Canyonlands landscape.[7]

Geography

The Colorado River and Green River combine within the park, dividing it into four distinct districts. Below the confluence, the Colorado River flows through Cataract Canyon.

The Island in the Sky district is a broad and level mesa to the north of the park between Colorado and Green river with many overlooks from the White Rim, a sandstone bench Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). below the Island, and the rivers, which are another Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). below the White Rim.

The Island in the Sky mesa/district of Canyonlands National Park, as seen from the Needles district

The Needles district is located east of the Colorado River and is named after the red and white banded rock pinnacles which dominate it, but various other forms of naturally sculptured rock such as canyons, grabens, potholes, and a number of arches similar to the ones of the nearby Arches National Park can be found as well. Unlike Arches National Park, where many arches are accessible by short to moderate hikes or even by car, most of the arches in the Needles district lie in back country canyons and require long hikes or four-wheel-drive trips to reach them.

The area was once home of the Ancestral Puebloans, of which many traces can be found. Although the items and tools they used have been largely taken away by looters, some of their stone and mud dwellings are well-preserved.[8] The Ancestral Puebloans also left traces in the form of petroglyphs, most notably on the so-called Newspaper Rock near the Visitor Center at the entrance of this district.

The Maze district is located west of the Colorado and Green rivers is the least accessible section of the park, and one of the most remote and inaccessible areas of the United States.[9][10]

A geographically detached section of the park located west-northwest of the main unit, Horseshoe Canyon Unit, contains panels of rock art made by hunter-gatherers from the Late Archaic Period (2000-1000 BC) pre-dating the Ancestral Puebloans.[11][12][13] Originally called Barrier Canyon, Horseshoe's artifacts, dwellings, pictographs, and murals are some of the oldest in America.[12] It is believed that the images depicting horses date from after 1540 AD, after the Spanish re-introduced horses to America.[12]

Climate

The National Weather Service has maintained two cooperative weather stations in the park since June 1965. Official data documents the desert climate with less than 10 inches (250 millimetres) of annual rainfall, as well as very warm, mostly dry summers and cold, occasionally wet winters. Snowfall is generally light during the winter.

Butte in Canyonlands, Horseshoe Canyon

The station in The Neck region reports average January temperatures ranging from a high of 37.0 °F (2.8 °C) to a low of 20.7 °F (−6.3 °C). Average July temperatures range from a high of 90.7 °F (32.6 °C) to a low of 65.8 °F (18.8 °C). There are an average of 43.3 days with highs of 90 °F (32 °C) or higher and an average of 124.3 days with lows of 32 °F (0 °C) or lower. The highest recorded temperature was 105 °F (41 °C) on July 15, 2005, and the lowest recorded temperature was −13 °F (−25 °C) on February 6, 1989. Average annual precipitation is 9.07 inches (230 mm). There are an average of 59 days with measurable precipitation. The wettest year was 1984, with 13.66 in (347 mm), and the driest year was 1989, with 4.63 in (118 mm). The most precipitation in one month was 5.19 in (132 mm) in October 2006. The most precipitation in 24 hours was 1.76 in (45 mm) on April 9, 1978. Average annual snowfall is 22.9 in (58 cm). The most snowfall in one year was 47.4 in (120 cm) in 1975, and the most snowfall in one month was 27.0 in (69 cm) in January 1978.[14]

4-second video of lightning striking near the Island in the Sky

The station in The Needles region reports average January temperatures ranging from a high of 41.2 °F (5.1 °C) to a low of 16.6 °F (−8.6 °C). Average July temperatures range from a high of 95.4 °F (35.2 °C) to a low of 62.4 °F (16.9 °C). There are an average of 75.4 days with highs of 90 °F (32 °C) or higher and an average of 143.6 days with lows of 32 °F (0 °C) or lower. The highest recorded temperature was 107 °F (42 °C) on July 13, 1971, and the lowest recorded temperature was −16 °F (−27 °C) on January 16, 1971. Average annual precipitation is 8.49 in (216 mm). There are an average of 56 days with measurable precipitation. The wettest year was 1969, with 11.19 in (284 mm), and the driest year was 1989, with 4.25 in (108 mm). The most precipitation in one month was 4.43 in (113 mm) in October 1972. The most precipitation in 24 hours was 1.56 in (40 mm) on September 17, 1999. Average annual snowfall is 14.4 in (37 cm). The most snowfall in one year was 39.3 in (100 cm) in 1975, and the most snowfall in one month was 24.0 in (61 cm) in March 1985.[15]

Geology

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A subsiding basin and nearby uplifting mountain range (the Uncompahgre) existed in the area in Pennsylvanian time. Seawater trapped in the subsiding basin created thick evaporite deposits by Mid Pennsylvanian. This, along with eroded material from the nearby mountain range, become the Paradox Formation, itself a part of the Hermosa Group. Paradox salt beds started to flow later in the Pennsylvanian and probably continued to move until the end of the Jurassic.[16] Some scientists believe Upheaval Dome was created from Paradox salt bed movement, creating a salt dome, but more modern studies show that the meteorite theory is more likely to be correct.

A warm shallow sea again flooded the region near the end of the Pennsylvanian. Fossil-rich limestones, sandstones, and shales of the gray-colored Honaker Trail Formation resulted. A period of erosion then ensued, creating a break in the geologic record called an unconformity. Early in the Permian an advancing sea laid down the Halgaito Shale. Coastal lowlands later returned to the area, forming the Elephant Canyon Formation.

Large alluvial fans filled the basin where it met the Uncompahgre Mountains, creating the Cutler red beds of iron-rich arkose sandstone. Underwater sand bars and sand dunes on the coast inter-fingered with the red beds and later became the white-colored cliff-forming Cedar Mesa Sandstone. Brightly colored oxidized muds were then deposited, forming the Organ Rock Shale. Coastal sand dunes and marine sand bars once again became dominant, creating the White Rim Sandstone.

Rock formations in the Needles district

A second unconformity was created after the Permian sea retreated. Flood plains on an expansive lowland covered the eroded surface and mud built up in tidal flats, creating the Moenkopi Formation. Erosion returned, forming a third unconformity. The Chinle Formation was then laid down on top of this eroded surface.

Increasingly dry climates dominated the Triassic. Therefore, sand in the form of sand dunes invaded and became the Wingate Sandstone. For a time climatic conditions became wetter and streams cut channels through the sand dunes, forming the Kayenta Formation. Arid conditions returned to the region with a vengeance; a large desert spread over much of western North America and later became the Navajo Sandstone. A fourth unconformity was created by a period of erosion.

Mud flats returned, forming the Carmel Formation and the Entrada Sandstone was laid down next. A long period of erosion stripped away most of the San Rafael Group in the area along with any formations that may have been laid down in the Cretaceous period.

The Laramide orogeny started to uplift the Rocky Mountains 70 million years ago and with it the Canyonlands region. Erosion intensified and when the Colorado River Canyon reached the salt beds of the Paradox Formation the overlying strata extended toward the river canyon, forming features such as The Grabens. Increased precipitation during the ice ages of the Pleistocene quickened the rate of canyon excavation along with other erosion. Similar types of erosion are ongoing, but occur at a slower rate.

Gallery

Further reading

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References

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External links