Оклахома, Техас және Канзас аймағының өсімдік жамылғысы

Ecoregion in Texas, Oklahoma, and Kansas
the city in Hickory County, Missouri

The term Cross Timbers, also known as Ecoregion 29, Central Oklahoma/Texas Plains, is used to describe a strip of land in the United States that runs from southeastern Kansas across Central Oklahoma to Central Texas. Made up of a mix of prairie, savanna, and woodland, it forms part of the boundary between the more heavily forested eastern country and the almost treeless Great Plains, and also marks the western habitat limit of many mammals and insects. These old growth forests contain millions of post oak from 200 to 400 years old and red cedar over 500 years old. 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 located on the very edge of the Great Plains, as they border directly parts of Level I Ecoregion 8.0, the Eastern Temperate Forests; elsewhere, the Cross Timbers are separated slightly from the Eastern Temperate Forests.

A much wider band than the Eastern Cross Timbers, the Western Cross Timbers band extends from far southern Oklahoma, including parts of Love and Carter counties, into central Texas, where it covers large parts of Montague, Young, Jack, Wise, Stephens, Palo Pinto, Parker, Eastland, Erath, Brown, San Saba, and Mills counties, as well as smaller parts of Clay, Cooke, Callahan, Hood, Coleman, and McCulloch counties. In Texas, this area includes the towns of Weatherford and Mineral Wells; Stephenville lies on the eastern fringe, while Brownwood is on the western edge. the hills are isolated, rugged, and scenic, with spectacular bluffs along the Brazos River as it flows through the region. Coal mining has historically been an important activity, as bituminous coal deposits are found throughout the region; indeed, the town of Newcastle in Young County was named after the English city of the same name due to the coal connection. In the mid to late 19th century, Comanche Indians occupied this area, and it became a flash point for conflict between various groups of white settlers, the Comanche, and the U. S. Cavalry; Forts Belknap and Richardson 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.

A fairly narrow strip dividing the Eastern and Western Cross Timbers, the Grand Prairie differs in physiography, topography, and land use from both of these, as it is much more nearly level and better suited to agriculture. Rachel Plummer, while a captive of the Comanche in 1836, described it as "a range of timber land from the waters of Arkansas, bearing a southwest direction, crossing the False Ouachita, Red River, the heads of Sabine, Angelina, Natchitoches, Trinity, Brazos, Colorado the range of timber is of an irregular width, say 5 to 35 miles wide abounding with small prairies, skirted with timber of various kinds — oak, of every description, ash, elm, hickory, walnut and mulberry the purest atmosphere I ever breathed was that of these regions." 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. Robert Neighbors and Rip Ford reached the "Cross Timbers, two parallel strips of timber region that ran down the middle of Texas", in 1849 while blazing an emigrant trail from Austin to El Paso.