The Ouachita Mountains (), simply referred to as the Ouachitas, are a
mountain range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...
in western
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
and southeastern
Oklahoma
Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...
. They are formed by a thick succession of highly deformed
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
strata constituting the Ouachita Fold and Thrust Belt, one of the important
orogenic belts
Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted t ...
of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
The Ouachitas continue in the subsurface to the northeast, where they make a poorly understood connection with the
Appalachians
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
and to the southwest, where they join with the
Marathon uplift
The Marathon Uplift is a Paleogene-age domal uplift, approximately in diameter, in southwest Texas. The Marathon Basin was created by erosion of Cretaceous and younger strata from the crest of the uplift.McBride, E.F. and Hayward, O.T., 1988''Ge ...
area of
West Texas
West Texas is a loosely defined region in the U.S. state of Texas, generally encompassing the arid and semiarid lands west of a line drawn between the cities of Wichita Falls, Abilene, and Del Rio.
No consensus exists on the boundary betwee ...
.
Together with the
Ozark Plateaus, the Ouachitas form the
U.S. Interior Highlands.
The highest natural point is
Mount Magazine
Mount Magazine, officially named Magazine Mountain, is the highest point of the U.S. Interior Highlands and the U.S. state of Arkansas, and is the site of Mount Magazine State Park. It is a flat-topped mountain or mesa capped by hard rock and r ...
at .
The Ouachita Mountains is a
Level III ecoregion designated by the
Environmental Protection Agency
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...
(EPA). The region has been subdivided into six
Level IV ecoregions.
Etymology
Louis R. Harlan claimed that "Ouachita" is composed of the
Choctaw
The Choctaw (in the Choctaw language, Chahta) are a Native American people originally based in the Southeastern Woodlands, in what is now Alabama and Mississippi. Their Choctaw language is a Western Muskogean language. Today, Choctaw people are ...
words ''ouac'' for "buffalo" and ''chito'' for "large", together meaning "country of large buffaloes". At one time, herds of
buffalo inhabited the lowland areas of the Ouachitas.
Historian
Muriel H. Wright wrote that "Ouachita" is composed of the
Choctaw
The Choctaw (in the Choctaw language, Chahta) are a Native American people originally based in the Southeastern Woodlands, in what is now Alabama and Mississippi. Their Choctaw language is a Western Muskogean language. Today, Choctaw people are ...
words ''owa'' for "hunt" and ''chito'' for "big", together meaning "big hunt far from home".
According to the article ''Ouachita'' in the ''
Encyclopedia of Oklahoma History and Culture
The Oklahoma Historical Society (OHS) is an agency of the government of Oklahoma dedicated to promotion and preservation of Oklahoma's history and its people by collecting, interpreting, and disseminating knowledge and artifacts of Oklahoma. ...
'', "Ouachita" comes from the French spelling of the
Caddo
The Caddo people comprise the Caddo Nation of Oklahoma, a federally recognized tribe headquartered in Binger, Oklahoma. They speak the Caddo language.
The Caddo Confederacy was a network of Indigenous peoples of the Southeastern Woodlands, wh ...
word ''washita'', meaning "good hunting grounds".
Geography
The Ouachitas are a major physiographic province of
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
and
Oklahoma
Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...
and are generally grouped with the
Arkansas River Valley
The Arkansas River Valley (usually shortened to River Valley) is a region in Arkansas defined by the Arkansas River in the western part of the state. Generally defined as the area between the The Ozarks, Ozark and Ouachita Mountains, the River V ...
. Together with the
Ozark Plateaus, the Ouachitas form the
U.S. Interior Highlands, one of few mountainous regions between the
Appalachians
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
and
Rockies
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
.
Flora
The Ouachitas are dominated by pine, oak, and hickory.
The shortleaf pine (''
Pinus echinata
''Pinus echinata'', the shortleaf pine, is a species of pine native to the southeastern United States.
Description
The tree is variable in form, sometimes straight, sometimes crooked, with an irregular crown. The tree reaches heights of with a ...
'') and post oak (''
Quercus stellata
''Quercus stellata'', the post oak or iron oak, is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry areas on the edges of fields, tops of ridges also grows in poor soils, and is resistant to r ...
'') thrive in dry, nutrient-poor soil and are common in upland areas. The maple-leaf oak (''
Quercus acerifolia
''Quercus acerifolia'' (also called maple-leaf oak) is a rare North American species of oak in the red oak section of ''Quercus'' (known as ''Lobatae''). It is endemic to just four locations within the Ouachita Mountains of the State of Arkansas ...
'') is found at only four sites worldwide, all of which are in the Ouachitas.
Some native tree species, such as the eastern red-cedar (''
Juniperus virginiana
''Juniperus virginiana'', also known as red cedar, eastern red cedar, Virginian juniper, eastern juniper, red juniper, and other local names, is a species of juniper native to eastern North America from southeastern Canada to the Gulf of Mexico a ...
''), are colonizers of human-disturbed sites.
The
Ouachita National Forest
The Ouachita National Forest is a vast congressionally-designated United States National Forest, National Forest that lies in the western portion of Arkansas and portions of extreme-eastern Oklahoma, USA.
History
The Ouachita National Forest is t ...
covers approximately 1.8 million acres of the Ouachitas.
It is one of the largest and oldest national forests in the
Southern U.S., created through an executive order by President
Theodore Roosevelt
Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or by his initials, T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26t ...
on December 18, 1907.
There are six wilderness areas within the
Ouachita National Forest
The Ouachita National Forest is a vast congressionally-designated United States National Forest, National Forest that lies in the western portion of Arkansas and portions of extreme-eastern Oklahoma, USA.
History
The Ouachita National Forest is t ...
, which are protected areas designed to minimize the impacts of human activities.
Several plants are
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the Ouachitas, including: ''
Agalinis nuttallii'',
''Cardamine angustata'' var. ''ouachitana'', ''
Carex latebracteata,
''Carex'' is a vast genus of more than 2,000 species of grass-like plants in the family (biology), family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those ...
''
''Galium arkansanum'' var. ''pubifolium'', ''
Houstonia ouachitana
''Houstonia ouachitana'', the Ouachita bluet, is a species of plants in the Rubiaceae, coffee family. It is endemic to the Ouachita Mountains of Arkansas and Oklahoma. It is an herb up to 20 cm tall, with lanceloate basal leaves and narrowly ...
'', ''
Hydrophyllum brownei'', ''
Liatris compacta'', ''
Quercus acerifolia
''Quercus acerifolia'' (also called maple-leaf oak) is a rare North American species of oak in the red oak section of ''Quercus'' (known as ''Lobatae''). It is endemic to just four locations within the Ouachita Mountains of the State of Arkansas ...
'', ''
Polymnia cossatotensis
''Polymnia'' is a genus of American plants in the sunflower family. It is the only genus in the tribe ''Polymnieae''. Several species are known by the common name leafcup.
; Species[Solidago ouachitensis
''Solidago ouachitensis'' is a North American species of flowering plants in the family Asteraceae known by the common name Ouachita Mountain goldenrod. It has a very limited range, found only in the Ouachita Mountains along the border between Ar ...]
'', ''
Spiranthes niklasii'' (near endemic, also found on
Crowley's Ridge
Crowley's Ridge (also Crowleys Ridge) is a geological formation that rises 250 to above the alluvial plain of the Mississippi embayment in a line from southeastern Missouri to the Mississippi River near Helena, Arkansas. It is the most prom ...
),
''Streptanthus maculatus'' subsp. ''obtusifolius'', ''
Streptanthus squamiformis'', ''
Valerianella palmerii'', and ''
Vernonia lettermanii''.
Fauna
Bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...
and
elk
The elk (''Cervus canadensis''), also known as the wapiti, is one of the largest species within the deer family, Cervidae, and one of the largest terrestrial mammals in its native range of North America and Central and East Asia. The common ...
once found habitat in the Ouachita Mountains, but have since been extirpated. Today, there are large populations of
white-tailed deer
The white-tailed deer (''Odocoileus virginianus''), also known as the whitetail or Virginia deer, is a medium-sized deer native to North America, Central America, and South America as far south as Peru and Bolivia. It has also been introduced t ...
,
coyote
The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...
, and other common temperate forest animals. Though elusive, hundreds of
black bear
Black bear or Blackbear may refer to:
Animals
* American black bear (''Ursus americanus''), a North American bear species
* Asian black bear (''Ursus thibetanus''), an Asian bear species
Music
* Black Bear (band), a Canadian First Nations group ...
roam the Ouachitas. Several
cryptic species
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
of
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
are endemic to the Ouachitas and have traits that vary from one locale to another.
Subranges
Athens Plateau
The Athens Plateau or Athens Piedmont (EPA Level IV ecoregion 36a) consists of a series of low relief ridges, none exceeding . It is located south of the Ouachitas and extends from to the Arkansas-Oklahoma border. The Athens Piedmont runs from
Arkadelphia, Arkansas
Arkadelphia is a city in Clark County, Arkansas, United States. As of the 2010 census, the population was 10,714. The city is the county seat of Clark County. It is situated at the foothills of the Ouachita Mountains. Two universities, Henderson ...
into Oklahoma through
Clark
Clark is an English language surname, ultimately derived from the Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone who was educate ...
,
Howard
Howard is an English-language given name originating from Old French Huard (or Houard) from a Germanic source similar to Old High German ''*Hugihard'' "heart-brave", or ''*Hoh-ward'', literally "high defender; chief guardian". It is also probabl ...
,
Pike
Pike, Pikes or The Pike may refer to:
Fish
* Blue pike or blue walleye, an extinct color morph of the yellow walleye ''Sander vitreus''
* Ctenoluciidae, the "pike characins", some species of which are commonly known as pikes
* ''Esox'', genus of ...
, and
Sevier counties in Arkansas and
McCurtain County
McCurtain County is in the southeastern corner of the U.S. state of Oklahoma. As of the 2010 census, the population was 33,151. Its county seat is Idabel. It was formed at statehood from part of the earlier Choctaw Nation in Indian Territory ...
in Oklahoma. The ecoregion's low ridges and hills are widely underlain by
Mississippian Stanley Shale in contrast to other parts of the Ouachitas.
Today, pine plantations are widespread; they are far more extensive than in the more rugged parts of the Arkansas Ouachitas. Pastureland and hayland also occur. Cattle and broiler chickens are important farm products.
The Caddo, Cossatot, and Missouri mountains are a high, compact group of mountains composed of the weather-resistant Arkansas Novaculite. They are located primarily in
Montgomery and
Polk
Polk may refer to:
People
* James K. Polk, 11th president of the United States
* Polk (name), other people with the name
Places
*Polk (CTA), a train station in Chicago, Illinois
* Polk, Illinois, an unincorporated community
* Polk, Missouri ...
counties, Arkansas. The highest natural point is Raspberry Mountain at . The headwaters of multiple rivers are found in this area, including the
Caddo
The Caddo people comprise the Caddo Nation of Oklahoma, a federally recognized tribe headquartered in Binger, Oklahoma. They speak the Caddo language.
The Caddo Confederacy was a network of Indigenous peoples of the Southeastern Woodlands, wh ...
,
Cossatot, and
Little Missouri rivers.
The Cross Mountains are located in
Polk
Polk may refer to:
People
* James K. Polk, 11th president of the United States
* Polk (name), other people with the name
Places
*Polk (CTA), a train station in Chicago, Illinois
* Polk, Illinois, an unincorporated community
* Polk, Missouri ...
and
Sevier counties, Arkansas and
McCurtain County, Oklahoma
McCurtain County is in the southeastern corner of the U.S. state of Oklahoma. As of the 2010 census, the population was 33,151. Its county seat is Idabel. It was formed at statehood from part of the earlier Choctaw Nation in Indian Territory. ...
. The highest natural point is Whiskey Peak at .
The Crystal Mountains are located primarily in
Montgomery County, Arkansas
Montgomery County is a county in the U.S. state of Arkansas. As of the 2010 census, the population was 9,487. The county seat is Mount Ida. Montgomery County is Arkansas's 45th county, formed on December 9, 1842, and named after Richard Montgom ...
. They are so named because of the occurrence of some of the world's finest
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
. The Crystal Mountains are generally taller than the nearby Zig Zag Mountains, achieving elevations over .
Fourche Mountains
The Fourche Mountains (EPA Level IV ecoregion 36d) are a long, continuous chain of east-west mountains composed of the weather-resistant
Jackfork Sandstone. They extend from
Pulaski County, Arkansas
Pulaski County is located in the U.S. state of Arkansas with a population of 399,125, making it the most populous county in Arkansas. The county is included in the Little Rock–North Little Rock– Conway metropolitan area. Its county seat is L ...
to
Atoka County, Oklahoma
Atoka County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 14,007. Its county seat is Atoka. The county was formed before statehood from Choctaw Lands, and its name honors a Choctaw Chief named A ...
and are home to several popular sites of interest, including
Pinnacle Mountain State Park
Pinnacle Mountain State Park is a 2,356-acre state park located in Pulaski County, Arkansas just outside of Little Rock. The main attraction is Pinnacle Mountain, an iconic landmark surrounded by the bottomlands of the Big Maumelle and Little Ma ...
near
Little Rock, Arkansas
(The Little Rock, The "Little Rock")
, government_type = council-manager government, Council-manager
, leader_title = List of mayors of Little Rock, Arkansas, Mayor
, leader_name = Frank Scott Jr.
, leader_ ...
. The highest natural point is
Rich Mountain at , which intersects the Arkansas-Oklahoma border near
Mena, Arkansas
Mena ( ) is a city in Polk County, Arkansas, United States. It is also the county seat of Polk County. The population was 5,558 as of the 2020 census. Mena is included in the Ark-La-Tex socio-economic region. Surrounded by the Ouachita National F ...
.
The Fourche Mountains are the archetypal Ouachita Mountains. Forested ridges are heavily forested with oak–hickory–pine forest; intervening valleys are cut into shale. Ridges are longer, habitat continuity is greater, the lithologic mosaic is different, and the topographic orientation is more consistent than in other parts of the Ouachitas. Differences in moisture and temperature between north- and south-facing slopes significantly influence native plant communities; they are products of the prevailing topographic trend.
Forests on steep, north-facing slopes are more
mesic than on southern aspects; the steepest, south-facing slopes contain shallow, moisture deficient soils supporting shrubs and rocky glades or grassy woodlands.
Pastureland and hayland are restricted to a few broad valleys. Logging is not nearly as intensive as in the commercial pine plantations of the less rugged Athens Plateau. Nutrient, mineral, and biochemical water quality parameter concentrations are low in the surface waters of the Fourche range, but
turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality.
Fluids can ...
can be higher than in other mountainous parts of the Ouachitas.
Although most streams stop flowing during the driest part of the summer, enduring deep pools, high quality habitat, and good water quality allow sensitive aquatic species to survive through the summer.
They are the only home and namesake of the
Fourche Mountain salamander.
The Fourche Mountains form a major watershed divide between the Arkansas River Basin to the north and the Red River Basin to the south.
The Frontal Ouachita Mountains are located in the
Arkansas River Valley
The Arkansas River Valley (usually shortened to River Valley) is a region in Arkansas defined by the Arkansas River in the western part of the state. Generally defined as the area between the The Ozarks, Ozark and Ouachita Mountains, the River V ...
and feature a number of isolated landforms. The highest natural point is
Mount Magazine
Mount Magazine, officially named Magazine Mountain, is the highest point of the U.S. Interior Highlands and the U.S. state of Arkansas, and is the site of Mount Magazine State Park. It is a flat-topped mountain or mesa capped by hard rock and r ...
at , which is also the highest natural point of the Ouachitas and
U.S. Interior Highlands. The Frontal Ouachita Mountains are structurally quite different from the rest of the Ouachitas and are sometimes considered a separate range.
The Trap Mountains are located primarily in
Garland
A garland is a decorative braid, knot or wreath of flowers, leaves, or other material. Garlands can be worn on the head or around the neck, hung on an inanimate object, or laid in a place of cultural or religious importance.
Etymology
From the ...
and
Hot Spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
counties,
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
. The highest natural point is Trap Mountain at .
The Zig Zag Mountains are located in
Garland County, Arkansas
Garland County is located in the U.S. state of Arkansas. As of the 2020 census, the population was 100,180. The county seat is Hot Springs.
Garland County comprises the Hot Springs, AR Metropolitan Statistical Area. The county includes Hot S ...
and are home to the thermal springs of
Hot Springs National Park
Hot Springs National Park is an American national park in central Garland County, Arkansas, adjacent to the city of Hot Springs, the county seat. Hot Springs Reservation was initially created by an act of the United States Congress on April 20, 18 ...
. They are so named because of their unique chevron shape when viewed from above, the result of plunging
anticline
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...
s and
syncline
In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimpose ...
s. The Zig Zag Mountains are not exceptionally tall, but do reach heights over .
Geology
The Ouachitas are formed by a thick succession of highly deformed
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
strata constituting the Ouachita Fold and Thrust Belt, which crops out for approximately in western
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
and southeastern
Oklahoma
Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...
.
In a general sense, the Ouachitas are considered an anticlinorium because the oldest known rocks are located towards the center of the outcrop area.
The Ouachitas continue in the subsurface to the
Black Warrior Basin
The Black Warrior Basin is a geologic sedimentary basin of western Alabama and northern Mississippi in the United States. It is named for the Black Warrior River and is developed for coal and coalbed methane production, as well as for convention ...
of
Alabama
(We dare defend our rights)
, anthem = "Alabama (state song), Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery, Alabama, Montgomery
, LargestCity = Huntsville, Alabama, Huntsville
, LargestCounty = Baldwin County, Al ...
and
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
where they plunge towards the
Appalachian Mountains
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
. To the southwest, the Ouachitas join with the Marathon area of west
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
where rocks of the Ouachita Fold and Thrust Belt are briefly exposed.
Unlike many ranges in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, the Ouachitas are mostly east-west trending. They are unique because
metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chem ...
and
volcanism
Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called ...
, features that are common in orogenic belts, are notably absent (with the exception of some low-grade
metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chem ...
). Due to the high degree of folding and faulting, the Ouachitas are clustered into distinct subranges, with ridges separated by relatively broad valleys.
The Ouachitas are known for some of the world's finest
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
, especially around
Mount Ida, Arkansas
Mount Ida is a city in and county seat of Montgomery County, Arkansas, United States. Founded in 1842, the city saw a silver boom in the 1880s bring early prosperity and economic development to the area.
Today, the economy is largely ranching, p ...
, the quartz capital of the world. The quartz formed after the
Ouachita Orogeny
The Ouachita orogeny was a mountain-building event that resulted in the folding and faulting of strata currently exposed in the Ouachita Mountains. The more extensive Ouachita system extends from the current range in Arkansas and Oklahoma south ...
when fractures in rocks filled with silica-saturated fluids and, over millions of years, precipitated crystals up to several feet in length. The Ouachitas are also known for
novaculite
Novaculite, also called Arkansas Stone, is a microcrystalline to cryptocrystalline rock type that consists of silica in the form of chert or flint. It is commonly white to grey or black in color, with a specific gravity that ranges from 2.2 to 2.5 ...
, a variety of
chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...
that has undergone low-grade
metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chem ...
; particular grades found only in
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
are used for making
whetstones.
History
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
through
Mississippian strata of the Ouachitas were deposited in a narrow, two-sided basin called the Ouachita Trough, which formed as part of a
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
failed rift system.
Succeeding
Pennsylvanian strata of the Ouachitas were deposited in a
foreland basin
A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithospher ...
during the early stages of the
Ouachita Orogeny
The Ouachita orogeny was a mountain-building event that resulted in the folding and faulting of strata currently exposed in the Ouachita Mountains. The more extensive Ouachita system extends from the current range in Arkansas and Oklahoma south ...
.
Subduction of the
South American Plate
The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mid-A ...
beneath the
North American Plate
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...
resulted in this mountain-building event.
Compressional forces caused the crust to buckle, producing complex folds at all scale levels and several overturned sequences.
The area of greatest deformation occurred in the Benton-Broken Bow Uplift, which extends from
Benton, Arkansas
Benton is a city in and the county seat of Saline County, Arkansas, United States and a suburb of Little Rock. It was established in 1837. At the 2010 census, the city had a population of 30,681. In 2019 the population was estimated at 36,820. ...
to
Broken Bow, Oklahoma
Broken Bow is a city in McCurtain County, Oklahoma, United States. The population was 4,120 at the 2010 census. It is named after Broken Bow, Nebraska, the former hometown of the city's founders, the Dierks brothers. Other Dierks-associate ...
.
The total height of the Ouachitas is not known, though they may have exceeded (based loosely on geologic cross-sections).
The terrain has been deeply eroded since the late
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
.
Stratigraphy
The Ouachitas are composed of
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
through
Pennsylvanian sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s. The Collier Shale, located at the core of the Benton-Broken Bow Uplift, is the oldest exposed formation of the Ouachitas. The
Atoka Formation, which was deposited much later during the
Pennsylvanian, has the largest areal extent of any of the
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
formations in
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
.
The geologic formations of the Ouachitas are as follows (in order of ascending age).
History
The mountains were home to the
Ouachita tribe The Ouachita are a Native Americans in the United States, Native American tribe who lived in northeastern Louisiana along the Ouachita River. Their name has also been pronounced as Washita by English speakers. The spelling "Ouachita" and pronunciati ...
, for which they were named. Later French explorers translated the name to its present spelling. The first recorded exploration was in 1541 by
Hernando de Soto
Hernando de Soto (; ; 1500 – 21 May, 1542) was a Spanish explorer and '' conquistador'' who was involved in expeditions in Nicaragua and the Yucatan Peninsula. He played an important role in Francisco Pizarro's conquest of the Inca Empire ...
. Later, in 1804,
President Jefferson
Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Fathers of the United States, Founding Father who served as the third president of the United States from 18 ...
sent
William Dunbar
William Dunbar (born 1459 or 1460 – died by 1530) was a Scottish makar, or court poet, active in the late fifteenth and early sixteenth centuries. He was closely associated with the court of King James IV and produced a large body of work in ...
and Dr. George Hunter to the area after the
Louisiana Purchase
The Louisiana Purchase (french: Vente de la Louisiane, translation=Sale of Louisiana) was the acquisition of the territory of Louisiana by the United States from the French First Republic in 1803. In return for fifteen million dollars, or app ...
.
Hot Springs National Park
Hot Springs National Park is an American national park in central Garland County, Arkansas, adjacent to the city of Hot Springs, the county seat. Hot Springs Reservation was initially created by an act of the United States Congress on April 20, 18 ...
became one of the nation's first parks in 1832. The
Battle of Devil's Backbone
The Battle of Devil's Backbone, also known as the Action at Devil's Backbone, was a military engagement in the Trans-Mississippi Theater of the American Civil War. Devil's Backbone is a ridge in the Ouachita Mountains approximately southwest of ...
was fought here at the ridge of the same name in 1863. In August 1990, the
U.S. Forest Service
The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages of land. Major divisions of the agency in ...
discontinued
clearcutting
Clearcutting, clearfelling or clearcut logging is a forestry/ logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of fore ...
as the primary tool for harvesting and regenerating short leaf, pine and hardwood forests in the Ouachita National Forest.
Tourism
The Ouachita Mountains contain the
Ouachita National Forest
The Ouachita National Forest is a vast congressionally-designated United States National Forest, National Forest that lies in the western portion of Arkansas and portions of extreme-eastern Oklahoma, USA.
History
The Ouachita National Forest is t ...
,
Hot Springs National Park
Hot Springs National Park is an American national park in central Garland County, Arkansas, adjacent to the city of Hot Springs, the county seat. Hot Springs Reservation was initially created by an act of the United States Congress on April 20, 18 ...
and
Lake Ouachita
Lake Ouachita (''Pronounced WAH-shi-tah'') is a reservoir created by the damming of the Ouachita River by Blakely Mountain Dam ().
Blakely Mountain Dam was built by the United States Army Corps of Engineers from 1948 to 1953 for hydroelectric p ...
, as well as numerous state parks and scenic byways mostly throughout Arkansas. They also contain the
Ouachita National Recreation Trail
Ouachita National Recreation Trail is a long, continuous hiking trail through the Ouachita Mountains
of Oklahoma and Arkansas. It is the longest backpacking trail in the Ouachita National Forest, spanning 192 miles across its length. Approximat ...
, a hiking trail through the heart of the mountains. The trail runs from Talimena State Park in Oklahoma to
Pinnacle Mountain State Park
Pinnacle Mountain State Park is a 2,356-acre state park located in Pulaski County, Arkansas just outside of Little Rock. The main attraction is Pinnacle Mountain, an iconic landmark surrounded by the bottomlands of the Big Maumelle and Little Ma ...
near
Little Rock
( The "Little Rock")
, government_type = Council-manager
, leader_title = Mayor
, leader_name = Frank Scott Jr.
, leader_party = D
, leader_title2 = Council
, leader_name2 ...
. It is a well maintained, premier trail for hikers, backpackers, and mountain bikers (for only selected parts of the trail).
The
Talimena Scenic Drive
The Talimena Scenic Drive is a National Scenic Byway in Kiamichi Country, southeastern Oklahoma and extreme western Arkansas spanning a stretch of Oklahoma State Highway 1 (SH-1) and Arkansas Highway 88 (AR 88) from Talihina, Oklahoma, to ...
begins at
Mena
MENA, an acronym in the English language, refers to a grouping of countries situated in and around the Middle East and North Africa. It is also known as WANA, SWANA, or NAWA, which alternatively refers to the Middle East as Western Asia (or a ...
, and traverses of Winding Stair and Rich Mountains, long narrow east-west ridges which extend into Oklahoma.
Rich Mountain reaches an elevation of in Arkansas near the Oklahoma border. The two lane winding road is similar in routing, construction, and scenery to the
Blue Ridge Parkway
The Blue Ridge Parkway is a National Parkway and All-American Road in the United States, noted for its scenic beauty. The parkway, which is America's longest linear park, runs for through 29 Virginia and North Carolina counties, linking Shenand ...
of the
Appalachian Mountains
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
.
[http://www.trais.com/tcatalog_trail.aspx?trailid=XFA101-040 , accessed 11 Mar 2011]
Sites of interest
*
Beavers Bend State Park
Beavers Bend State Park is a Oklahoma state park located in McCurtain County. It is approximately north of Broken Bow on SH-259A. It was established in 1937 and contains Broken Bow Lake.
*
Black Fork Mountain Wilderness
The Black Fork Mountain Wilderness Area is located in the U.S. states of Arkansas and Oklahoma. Created by an act of Congress in 1984, the wilderness covers an area of 13,139 acres (53 km²). The Arkansas portion contains and the Oklahoma p ...
*
Caney Creek Wilderness
The Caney Creek Wilderness is a rugged 14,460-acre (58.5 km2) segment of the Ouachita National Forest just outside of the mountain town of Mena, Arkansas. It was designated by Congress in 1975 as the first wilderness area in Arkansas. The wild ...
*
Cossatot River State Park-Natural Area
Cossatot River State Park-Natural Area is a Arkansas state park in Howard County and Polk County, Arkansas in the United States. The park follows a rough, undeveloped of the Cossatot River. The river itself is included in Arkansas's Natura ...
*
Flatside Wilderness
*
Heavener Runestone Park
*
Hot Springs National Park
Hot Springs National Park is an American national park in central Garland County, Arkansas, adjacent to the city of Hot Springs, the county seat. Hot Springs Reservation was initially created by an act of the United States Congress on April 20, 18 ...
*
Jack Creek Recreation Area
*
Lake Catherine
*
Lake Hamilton
*
Lake Maumelle
Lake Maumelle is a man-made lake in central Arkansas, United States, in Pulaski County, and covers 8,900 acres. It is one of the primary drinking water sources for Little Rock, Arkansas
( The "Little Rock")
, government_type = C ...
*
Lake Ouachita
Lake Ouachita (''Pronounced WAH-shi-tah'') is a reservoir created by the damming of the Ouachita River by Blakely Mountain Dam ().
Blakely Mountain Dam was built by the United States Army Corps of Engineers from 1948 to 1953 for hydroelectric p ...
*
Mount Magazine State Park
*
Pinnacle Mountain State Park
Pinnacle Mountain State Park is a 2,356-acre state park located in Pulaski County, Arkansas just outside of Little Rock. The main attraction is Pinnacle Mountain, an iconic landmark surrounded by the bottomlands of the Big Maumelle and Little Ma ...
*
Queen Wilhelmina State Park
Queen Wilhelmina State Park is a unit of Arkansas Department of Parks and Tourism in the Ouachita Mountains.
The original "Castle in the Sky" lodge was built in 1898 on 2,681-foot Rich Mountain, in Polk County, Arkansas. The park is on Talimena ...
*
Mount Nebo State Park
Located near Dardanelle, Arkansas and rising about above the mountain valleys of west-central Arkansas to an elevation of about above sea level, Mount Nebo has views of Lake Dardanelle, the Arkansas River and the surrounding mountain ridges. Ato ...
References
Further reading
James B. Calvert, 2003, ''The Ouachita System'', University of Denver
External links
dead link, date]
Friends of the Ouachita Trail (FoOT)Lakeouachita.org: Lake Ouachita— ''largest lake in the Ouachita Mountains''.
{{Authority control
Ouachita Mountains,
Mountain ranges of Arkansas
Mountain ranges of Oklahoma
Ouachita National Forest
U.S. Interior Highlands
Arkansas placenames of Native American origin
Landforms of Scott County, Arkansas
Landforms of Montgomery County, Arkansas
Landforms of Le Flore County, Oklahoma
Landforms of Polk County, Arkansas
Landforms of Yell County, Arkansas
Landforms of McCurtain County, Oklahoma
Landforms of Garland County, Arkansas
Landforms of Perry County, Arkansas
Landforms of Saline County, Arkansas
Landforms of Sebastian County, Arkansas
Landforms of Logan County, Arkansas
Landforms of Pike County, Arkansas
Landforms of Ashley County, Arkansas
Landforms of Howard County, Arkansas
Landforms of Hot Spring County, Arkansas