The term
Cross Timbers is used to describe a fairly narrow strip of land in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
that runs from southeastern
KansasKansas is a state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa tribe, who inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south wind," although this was...
across
Central OklahomaCentral Oklahoma is the geographical name for the central region of the U.S. state of Oklahoma. It is also known by the Oklahoma Department of Tourism designation, Frontier Country....
to Central Texas. Made up of a mix of
prairiePrairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...
,
savannaA savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close...
, and
woodlandEcologically, a woodland is an area covered in trees, usually at low density, forming an open habitat, allowing sunlight to penetrate between the trees, and limiting shade. Woodland may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to...
, it forms part of the boundary between the more heavily forested eastern part of the country and the almost treeless
Great PlainsThe Great Plains are the broad expanse of prairie and steppe which lie west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...
, and also marks the western
habitatThe term habitat has a number of meanings:* Habitat , a place where a species lives and grows** Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
limit of many
mammalMammals are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both males and females are characterized by sweat glands, hair, three middle ear bones used in hearing, and a neocortex region in the brain.Mammals are divided into three main...
s and
insectInsects are arthropods, having a hard exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae. They are the most diverse group of animals on the planet and include more than a million species that are already described. Insects represent more than half of all...
s.
No major metropolitan areas lie wholly within the Cross Timbers, although roughly the western half of the Dallas-Fort Worth Metroplex does, including the cities of Fort Worth, Denton, Arlington, and Weatherford. The western
suburbSuburbs are defined in various different ways around the world. They can be the residential areas of a large city, or separate residential communities within commuting distance of a city. Some suburbs have a degree of political autonomy, and most have lower population density than inner city...
s of the
Tulsa metropolitan areaU.S. Census Bureau Areas|-! colspan="2" | |-! colspan="2" style="background:#d8d8e8;color:#000;" | Tulsa Metropolitan Area
|-| Common names || Green Country, Tulsa Metro Area|-...
and the northeastern suburbs of the
Oklahoma City metropolitan areaThe Oklahoma City Metropolitan Area is a large urban region located in the central part of the state of Oklahoma. It is often known as Oklahoma City Metroplex or Greater Oklahoma City, and contains the state capital and principal city, Oklahoma City.Seven counties make up the Oklahoma City...
also lie within this area. The main highways that cross the region are I-35 and I-35W going north to south (although they tend to skirt the Cross Timbers' eastern fringe south of Fort Worth) and I-40 going east to west. Numerous U.S. Highways also cross the area.
As an ecoregionAn ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area smaller than a "realm" or "ecozone". Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species...
The Cross Timbers are defined by the United States
Environmental Protection AgencyThe U.S. Environmental Protection Agency is an agency of the federal government of the United States charged to regulate chemicals and protect human health by safeguarding the natural environment: air, water, and land...
as
Ecoregion 29, a
Level III ecoregion. It is bordered on the west by the Central
Great PlainsThe Great Plains are the broad expanse of prairie and steppe which lie west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...
(Ecoregion 27), on the northwest by the
Flint HillsThe Flint Hills, historically known as Bluestem Pastures or Blue Stem Hills, are a band of hills in eastern Kansas stretching into north-central Oklahoma, extending from Marshall County in the north to Cowley County, Kansas and Osage County, Oklahoma in the south...
in Kansas (#28), on the northeast by the Central Irregular Plains (#40), on the east chiefly by the Arkansas Valley (#37) in
OklahomaOklahoma is a state located in the South Central region of the United States of America. With an estimated 3,617,316 residents in 2007 and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
and the Texas Blackland Prairies (#32) in
TexasTexas is the second-largest U.S. state in both area and population, and the largest state in the contiguous United States.The name had wide usage among native Americans, meaning "friends" or "allies"...
, and on the south by the
Edwards PlateauThe Edwards Plateau is a region of west-central Texas which is bounded by the Balcones Fault to the south and east, the Llano Uplift and the Llano Estacado to the north, and the Pecos River and Chihuahuan Desert to the west. San Angelo, Austin, San Antonio and Del Rio roughly outline the area...
(#30). Some organizations and maps refer to the Cross Timbers ecoregion as the
Central Oklahoma/Texas Plains.
The woodland and savanna portions of the Cross Timbers are mainly
post oakQuercus stellata is an oak in the white oak group. It is a small tree, typically 10–15 m tall and 30–60 cm trunk diameter, though occasional specimens reach 30 m tall and 140 cm diameter. It is native to the eastern United States, from Connecticut in the northeast, west to southern Iowa, southwest...
and
blackjack oakQuercus marilandica is a small oak, one of the red oak group Quercus sect. Lobatae, but fairly isolated from the others...
on coarse, sandy soils; fire suppression in recent years has increased forest density and allowed
Eastern redcedarJuniperus virginiana is a species of juniper native to eastern North America, from southeastern Canada to the Gulf of Mexico, east of the Great Plains...
to invade as well. The short, stout oaks that grow in the Cross Timbers were no good for timber and those that were not cleared for farmland constitute one of the least disturbed forest types in the eastern United States, with some of old-growth forest scattered throughout the region. These old-growth forests contain millions of post oak from 200 to 400 years old and redcedar over 500 years old. The prairie portions are chiefly
tallgrassThe tallgrass prairie is an ecosystem native to central North America, with fire as its primary periodic disturbance. In the past, tallgrass prairies covered a large portion of the American Midwest, just east of the Great Plains, and portions of the Canadian Prairies...
on finer, dry soils; overall, the Cross Timbers are not as
arableIn geography, arable land is an agricultural term, meaning land that can be used for growing crops. It is distinct from cultivated land and includes jungles that are not currently used for human purposes. Arable land covers an area of approximately 12 million square miles...
as the surrounding ecoregions. Today,
land useLand use is the human modification of natural environment or wilderness into built environment such as fields, pastures, and settlements. The major effect of land use on land cover since 1750 has been deforestation of temperate regions. More recent significant effects of land use include urban...
is a mixture of
rangelandRangeland refers to expansive, mostly unimproved lands on which a significant proportion of the natural vegetation is native grasses, grass-like plants, forbs, and shrubs. Rangeland also consists of areas seeded to native or adapted introduced species that are managed like native vegetation...
,
pasturePasture is land with low-growing vegetation cover used for grazing of livestock as part of a farm, or in ranching or other unenclosed pastoral systems. Prior to the advent of factory farming, pasture was the primary source of food for grazing animals such as cattle and horses...
s, and
farmlandFarmland may refer to:*Arable land, land used for agriculture*Farmland, Indiana, a town in the United States*Farmland Industries, founded in 1929 as the Union Oil Company, later renamed Consumers Cooperative Association and Farmland Industries, Inc....
. The area has also been an important site of oil extraction for over eighty years.
GeologicallyGeology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed...
speaking, the Cross Timbers are underlain by
PennsylvanianThe Pennsylvanian is in the ICS geologic timescale the youngest subperiod or upper subsystem of the Carboniferous period. It lasted from roughly to Ma . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the...
and
CretaceousThe Cretaceous , Latin language for "chalky", usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago . In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period of the...
-era
sandstoneSandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow,...
and
limestoneLimestone is a sedimentary rock composed largely of the mineral calcite . The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record...
that has been moderately
dissectedA dissected plateau is a plateau area that has been uplifted, then severely eroded so that the relief is sharp. Such an area may be referred to as mountainous, but dissected plateaus are distinguishable from orogenic mountain belts by the lack of folding, metamorphism, extensive faulting, or...
, giving the region a gently to moderately rolling
topographyTopography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
, including some
cuestaIn structural geology and geomorphology, a cuesta is a ridge formed by gently tilted sedimentary rock strata in a homoclinal structure. Cuestas have a steep slope, where the rock layers are exposed on their edges, called an escarpment or, if more steep, a cliff...
s. Although local
reliefTerrain, or relief, is the third or vertical dimension of land surface. When relief is described underwater, the term bathymetry is used...
is relatively low, it is generally greater than that in the surrounding ecoregions, although this is not the case with the Flint Hills in Kansas.
EcologicallyEcology is the interdisciplinary scientific study of the interactions between organisms and the interactions of these organisms with their environment....
, the EPA includes the Cross Timbers as part of the vast
Great PlainsThe Great Plains are the broad expanse of prairie and steppe which lie west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...
, which comprise
Level I Ecoregion 9.0, stretching from
central AlbertaCentral Alberta is a region located in the Canadian province of Alberta.Central Alberta is the most densely populated rural area in the province...
in
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
to northern
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. More specifically, the Cross Timbers fall into
Level II Ecoregion 9.4, the smaller South Central Semi-Arid Plains. In southern Oklahoma, the Cross Timbers are literally located on the very edge of the Great Plains, as they border directly onto parts of Level I Ecoregion 8.0, the Eastern Temperate Forests; elsewhere, the Cross Timbers are separated slightly from the Eastern Temperate Forests. In turn, the Cross Timbers are themselves subdivided into nine
Level IV Ecoregions:
29a: Northern Cross Timbers
A wide belt of land stretching from south-central Oklahoma into southeastern Kansas, this is the only part of the Cross Timbers that extends into Kansas. In that state, it covers eastern Chautauqua and Elk counties and smaller portions of Greenwood, Woodson, Wilson, and Montgomery counties, while in Oklahoma, this region covers all of Seminole, Pottawatomie, and Okfuskee counties, large parts of Osage, Lincoln, Creek, Oklahoma, Cleveland, Pontotoc, Hughes, McIntosh, and Okmulgee counties, and smaller parts of Logan, Garvin, Murray, Pawnee, Tulsa, Wagoner, and Washington counties. The towns of Sapulpa, Ada, and
Shawnee, OklahomaShawnee is a city in Pottawatomie County, Oklahoma, United States. The population was 28,692 at the 2000 census. The city is part of the Oklahoma City-Shawnee Combined Statistical Area; it is also the county seat of Pottawatomie County and the principal city of the Shawnee Micropolitan Statistical...
fall within this large area; Bartlesville and Okmulgee lie on the eastern edge.
29b: Eastern Cross Timbers
In Oklahoma, this belt of woodland covers all of Marshall County and parts of Love, Carter, Johnston, and Bryan counties, but in Texas, this region exists as a long, very narrow strip of dense forest stretching from the
Red RiverThis page is about the tributary of the Mississippi River; for the tributary of Lake Winnipeg, see the Red River of the North.
The Red River, or sometimes The Red River of the South, is a major tributary of the Mississippi and Atchafalaya Rivers located in the United States of America. The...
to just north of
Waco, TexasWaco is a city in and the county seat of McLennan County, Texas. The city has a 2008 estimated total population of 124,009. It is the 21st largest city by population in Texas, and 194th in the US...
. It passes through northwestern Grayson County, eastern Cooke, Denton and Tarrant counties, central Johnson County, western Hill County, and northern McClennan County. The city of
Arlington, TexasArlington is a city in Tarrant County, Texas within the Dallas-Fort Worth-Arlington metropolitan area. According to a U.S Census Bureau release, as of 2007 Arlington had an estimated population of 371,038...
lies within this zone, and Denton and Cleburne are on its western edge.
29c: Western Cross Timbers
A much wider band than the Eastern Cross Timbers, the Western Cross Timbers extend from far southern Oklahoma, including parts of
LoveLove County is a county located in the U.S. state of Oklahoma. As of 2000, the population is 8,831. Its county seat is Marietta.Love County is part of the Ardmore, Oklahoma, Micropolitan Statistical Area.-Geography:According to the U.S...
and
CarterCarter County is a county located in the U.S. state of Oklahoma. As of 2000, the population was 45,621. Its county seat is Ardmore.Carter County is part of the Ardmore, Oklahoma, Micropolitan Statistical Area...
counties, into central Texas, where it covers large parts of
MontagueMontague County is a county located in the U.S. state of Texas. In 2000, its population was 19,117. Montague is named for Daniel Montague, a surveyor and soldier in the Mexican-American War. The seat of the county is Montague....
,
YoungYoung County is a county located in the U.S. state of Texas. In 2000, its population was 17,943. Its county seat is Graham. The county is named for William Cocke Young, an early Texas settler and soldier.-Geography:According to the U.S...
,
JackJack County is a county located in the U.S. state of Texas. In 2000, its population was 8,763. Its county seat is Jacksboro. Jack County is named for Patrick Churchill Jack, and his brother William Houston Jack, both soldiers of the Texas Revolution....
,
WiseWise County is a county located in the U.S. state of Texas. As of 2000, the population was 48,793. Its county seat is Decatur. The county is named for Henry Alexander Wise, a U.S. Congressman from Virginia who supported Texas' annexation. Wise County is considered part of the Dallas-Fort Worth...
,
StephensStephens County is a county located in the U.S. state of Texas. In 2000, its population was 9,674. Its county seat is Breckenridge. The county was originally named Buchanan County, after U.S. President James Buchanan, but was renamed in 1861 for Alexander H. Stephens, the vice president of the...
,
Palo PintoPalo Pinto County is a county located in the U.S. state of Texas. In 2000, its population was 27,026. The seat of the county is Palo Pinto.Palo Pinto County is part of the Mineral Wells Micropolitan Statistical Area as well as the Dallas–Fort Worth Combined Statistical...
,
ParkerParker County is a county located in the U.S. state of Texas. In 2000, its population was 88,495; in 2005, its population was estimated to be 102,801. The county is part of the Dallas/Fort Worth Metroplex. Parker County is named for Isaac Parker, a state legislator who introduced the bill that...
,
EastlandEastland County is a county located in the U.S. state of Texas. In 2000, its population was 18,297. It is named for William Mosby Eastland, a soldier during the Texas Revolution and the only officer to die as a result of the so-called "Black Bean executions" of the ill-fated Mier_Expedition. The...
,
ErathErath County is a county located in the U.S. state of Texas. In 2000, its population was 33,001. It is named for George Bernard Erath, an early surveyor and a soldier at the Battle of San Jacinto. The seat of the county is Stephenville....
,
BrownBrown County is a county located in the U.S. state of Texas. As of 2000, the population was 37,674. Its county seat is Brownwood. Brown is named for Henry Stevenson Brown, a commander at the Battle of Velasco....
,
San SabaSan Saba County is a county located in the U.S. state of Texas. In 2000, its population was 6,186. Its county seat is San Saba. It is named for the San Saba River, which flows through the county....
, and
MillsMills County is a county located in the U.S. state of Texas. In 2000, its population was 5,151. Mills County is named for John T. Mills, a justice of the Texas Supreme Court. The seat of the county is Goldthwaite.-Geography:According to the U.S...
counties, as well as smaller parts of
ClayClay County is a county located in the U.S. state of Texas. Its name is in honor of Henry Clay, famous American statesman, member of the United States Senate from Kentucky and United States Secretary of State in the 19th century. It is part of the Wichita Falls, Texas, Wichita Falls metropolitan...
,
CookeCooke County is a county located in the U.S. state of Texas. In 2000, its population was 36,363. It is named for William Gordon Cooke, a soldier during the Texas Revolution. The county seat is Gainesville....
,
CallahanCallahan County is a county located in the U.S. state of Texas. As of 2000, the population was 12,905. It is included in the Abilene, Texas Metropolitan Statistical Area. Its county seat is Baird. Callahan is named for James Hughes Callahan, a soldier during the Texas...
,
HoodHood County is a county located in the U.S. state of Texas. In 2000, the population was 41,100. Its seat is Granbury. Hood County is named for John Bell Hood, a Confederate lieutenant general and the commander of Hood's Texas Brigade....
,
ColemanColeman County is a county located in the U.S. state of Texas. In 2000, its population was 9,235. It is named for Robert M. Coleman, a signer of the Texas Declaration of Independence and soldier at the Battle of San Jacinto. The seat of the county is Coleman....
, and
McCullochMcCulloch County is a county located in the U.S. state of Texas. In 2000, its population was 8,205. Its county seat is Brady. McCulloch is named for Benjamin McCulloch, a famous Texas Ranger and Confederate general.-Geography:According to the U.S...
counties. In Texas, this area includes the towns of
WeatherfordWeatherford is a city in Parker County, Texas, United States. The population was 19,000 at the 2000 census. It is the county seat of Parker County and is part of the Dallas-Fort Worth Metroplex....
and
Mineral WellsMineral Wells is a city in Palo Pinto County, Texas and a portion of Parker County, Texas. The population was 16,946 at the 2000 census. The city is named for mineral springs in the area, which were highly popular in the early 1900s...
;
StephenvilleStephenville is a city in and the county seat of Erath County, Texas, United States. The population was 14,921 at the 2000 census. Founded in 1856, it is home to Tarleton State University. Stephenville is among several communities that calls itself the "Cowboy Capital of the...
lies on the eastern fringe, while
BrownwoodBrownwood is a city in and the county seat of Brown County, Texas, United States. The population was 18,813 at the 2000 census.-History:During the Second World War, Brownwood was the location of U.S. Army Camp Bowie, which had a peak complement of over 80,000 soldiers...
is on the western edge.
The part of this region north of
I-20Interstate 20 in Texas is a major east-west Interstate Highway in the Southern United States, running east from a junction with Interstate 10 east of Kent, Texas, through the Dallas-Fort Worth Metroplex to the border with Louisiana near Waskom, Texas...
is sometimes colloquially referred to as the
Palo Pinto MountainsThe term Palo Pinto Mountains properly refers to a specific cuesta-like range of hills in western Palo Pinto County, Texas. The name Palo Pinto roughly translates to "painted stick" in reference to the cedar trees of the area...
; the hills are isolated, rugged, and scenic, with spectacular
bluffsIn geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are...
along the
Brazos RiverThe Brazos River, called the Rio de los Brazos de Dios by early Spanish explorers is the 11th longest river in the United States at 2060 km from its source of Blackwater Draw, Curry County, New Mexicoto its mouth at the Gulf of Mexico with a 116,000 km² drainage basin.-Geography:The Brazos...
as it flows through the region.
Coal miningCoal mining is the extraction or removal of coal from the earth by mining. When coal is used for fuel in power generation it is referred to as steaming or thermal coal. Coal that is used to create coke for steel manufacturing is referred to as coking or metallurgical coal...
has historically been an important activity, as
bituminous coalBituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than anthracite coal....
deposits are found throughout the region; indeed, the town of
NewcastleNewcastle is a city in Young County, Texas, United States. Following the beginning of coal mining in 1908, the town was established and named for the English coal town, Newcastle upon Tyne. Coal mining had ended by 1942...
in Young County was named after the
English cityNewcastle upon Tyne is a city and metropolitan borough of Tyne and Wear, in North East England...
of the same name due to the coal connection.
Historically speaking, in the mid-to-late 19th century,
ComancheThe Comanche are a Native American ethnic group whose range consisted of present-day eastern New Mexico, southern Colorado, northeastern Arizona, southern Kansas, all of Oklahoma, and most of northwest Texas. Originally, the Comanches were hunter-gatherers, with a typical Plains Indian culture....
IndiansNative Americans in the United States is the phrase that describes indigenous peoples from North America now encompassed by the continental United States, including parts of Alaska and the island state of Hawaii. They comprise a large number of distinct tribes, states, and ethnic groups, many of...
occupied this area, and it became a
flash pointIn international relations, a flashpoint is an area or dispute that has a strong possibility of developing into a war.- Current flashpoints :* the Taiwan straits* Korea peninsula* the Golan heights* Kashmir* the Spratly Islands...
for conflict between various groups of white settlers, the Comanche, and the U.S. Cavalry;
FortsThe Forts of Texas include a number of historical and operational military installations. For over two hundred years, various groups fought over access to or control over the region that is now Texas...
BelknapFort Belknap, located near Newcastle, Texas, was established in 1851 by brevet Brigadier William G. Belknap to protect the Texas frontier against raids by the Kiowa and Comanche. It was the northernmost fort in a line from the Rio Grande to the Red River...
and
RichardsonFort Richardson was an United States Army installation located one mile south of Jacksboro, Texas. Named in honor of Union General Israel B...
were built in the area to protect this part of the frontier.
Numerous roads cross this region, including US 70 in Oklahoma and I-20, I-30, US 67, US 81, US 82, US 180, US 183, US 281, US 287, and US 380 in Texas.
29d: Grand Prairie
A fairly narrow strip dividing the Eastern and Western Cross Timbers, the Grand Prairie differs in physiography,
topographyTopography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
, and land use from both of these, as it is much more nearly level and better suited to
agricultureAgriculture is the production of food and goods through farming and forestry. Agriculture was the key development that led to the rise of human civilization, with the husbandry of domesticated animals and plants creating food surpluses that enabled the development of more densely populated and...
. It includes a small part of
Love County, OklahomaLove County is a county located in the U.S. state of Oklahoma. As of 2000, the population is 8,831. Its county seat is Marietta.Love County is part of the Ardmore, Oklahoma, Micropolitan Statistical Area.-Geography:According to the U.S...
(the only part of this region outside of Texas) and passes south through western Cooke County, eastern Wise County, and western Denton, Tarrant, and Johnson counties, and also includes parts of Parker, Erath, Hood, Somervell, Hill, and McClennan counties. This region contains the cities of Fort Worth, Granbury and Denton, although Denton lies on the border with the Eastern Cross Timbers. I-35 and I-35W cross north to south, while US 82, US 380, I-30, I-20, US 377, and US 67 cross east to west; US 81 and US 287 also cross southwest to northeast.
29e: Limestone Cut Plains
A broader, southern extension of the Grand Prairie, found only in Texas; it is underlain by limestone rather than sandstone, and serves as a physiological and vegetational transition to the Edwards Plateau, which it borders to the south. All of Hamilton and Coryell counties, large parts of Bell, Lampasas, Mills, Erath, and Bosque counties, and smaller parts of Williamson, Burnet, Brown, Comanche, Hood, Somervell, and McClennan counties, including the towns of Killeen, Fort Hood, Copperas Cove, and Lampasas, fall within in this region. Among the few major roads that cross the Limestone Cut Plains are US 281 north to south and US 84 east to west.
29f: Carbonate Cross Timbers
This ecoregion exists as an enclave within the Western Cross Timbers, stretching from southern
Jack County, TexasJack County is a county located in the U.S. state of Texas. In 2000, its population was 8,763. Its county seat is Jacksboro. Jack County is named for Patrick Churchill Jack, and his brother William Houston Jack, both soldiers of the Texas Revolution....
across northwestern Palo Pinto County into eastern Stephens County, as well as tiny parts of Young and Eastland counties. The region features a limestone substrate as opposed to sandstone, and has greater topographical relief and denser and different vegetation than other parts of the Cross Timbers. No towns of any size lie within this area, although
Possum Kingdom LakePossum Kingdom Lake , located primarily in Palo Pinto County Texas, is a reservoir on the Brazos River in the Palo Pinto Mountains, known for its clear blue waters. It has a shore line. It is unusual for a Texas lake with average depths exceeding 80 ft and clear blue water vs...
and
State ParkPossum Kingdom State Park is a state park in Palo Pinto County, Texas, that was built in the 1940s by the Civilian Conservation Corps. It covers approximately , and lies in the Palo Pinto Mountains and Brazos River Valley of Texas. The park borders the large Possum Kingdom Lake, a lake known for...
do; the region is crossed by US 180 and Texas State Highway 16.
29g: Arbuckle Uplift
Covering a fairly small area in south-central Oklahoma and underlain by a unique mosaic of several different
mineralA mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific...
s, this region includes the town of Ardmore.
29h: Northwestern Cross Timbers
An extension in two branches of the Cross Timbers into southwestern Oklahoma, this area features reduced tree density and height, but also small forests dominated by
sugar mapleAcer saccharum is a species of maple native to the hardwood forests of northeastern North America, from Nova Scotia west to southern Ontario, and south to Georgia and Texas....
in deeper river canyons. The town of
Duncan, OklahomaDuncan is a city in Stephens County, Oklahoma, United States. The population was 22,505 at the 2000 census. It is the county seat of Stephens County.-Geography:Duncan is located at...
lies in this region.
29i: Arbuckle MountainsThe Arbuckle Mountains are an ancient mountain range in south-central Oklahoma in the United States. The Arbuckles date back to 540-440 million years ago in the latest Precambrian and earliest Paleozoic era, and reach a height of 1,412 feet above sea level....
A small area nestled in between regions 29g and h; it is made of
foldedThe term fold is used in geology when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of plastic deformation. Synsedimentary folds are those due to slumping of sedimentary material before it is lithified. Folds in rocks vary in size...
, rather than dissected, limestone, sandstone, and
dolomiteDolomite is the name of a sedimentary carbonate rock and a mineral, both composed of calcium magnesium carbonate CaMg
2 found in crystals....
, and features the greatest topographical relief of the entire Cross Timbers, though not the highest elevations. The landscape includes many caves,
sinkholeA sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the surface topography caused by the removal of soil or bedrock, often both, by water...
s,
springsA spring is any natural occurrence where water flows on to the surface of the earth from below the surface, and is thus where the aquifer surface meets the ground surface.- Formation :...
, and streams. I-35 crosses this region north to south.
History
The thick growth formed an almost impenetrable barrier for early American explorers and travelers.
Washington IrvingWashington Irving was an American author, essayist, biographer and historian of the early 19th century. He was best known for his short stories "The Legend of Sleepy Hollow" and "Rip Van Winkle", both of which appear in his book The Sketch Book of Geoffrey Crayon, Gent. His historical works...
, in 1835, described it as "like struggling through forests of cast iron." Josiah Gregg described the Cross Timbers in 1845 as varying in width from five to thirty miles and attributed their denseness to the continual burning of the prairies.
Additional reading
- Dale, Edward Everett. The Cross Timbers: Memories of a North Texas Boyhood. Austin, TX: University of Texas Press, 1966. ISBN 0-292-73611-8
- Roach, Joyce. Wild Rose: A Folk History of a Cross Timbers Settlement, Keller, Texas. Denton, TX: University of North Texas Press, 1996. ISBN 0898659728
External links