Texas Almanac, 1992-1993 Page: 73

ENVIRONMENT 73

NATURAL REGIONS
OF TEXAS
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able area in East Central Texas. Principal industry is di-
versified farming and livestock raising.
Throughout, it is spotty in character with some insu-
lar areas of blackland soil, and some that closely resem-
ble those of the Pine Belt. There is a small isolated area
of pines in Bastrop County known as the Lost Pines. The
Post Oak Belt has lignite, commercial clays and some
other minerals.
Blackland Belt
The Blackland Belt stretches from the Rio Grande to
the Red River, lying just below the line of the Balcones
Fault, and varying in width from 15 to 70 miles. It is nar-
rowest below the segment of the Balcones Fault from the
Rio Grande to Bexar County and gradually widens as it
runs northeast to the Red River. Its rolling prairie, easily
turned by the plow, developed rapidly as a farming area
until the 1930s and was the principal cotton-producing
area of Texas. Now, however, other Texas irrigated,
mechanized areas lead in farming. Because of the early
growth, the Blackland Belt is still the most thickly pop-
ulated area in the state and contains within it and along
its border more of the state's large and middle-sized cit-
ies than any other area. Primarily because of this con-
centration of population, this belt has the most
diversified manufacturing industry of the state.
Coastal Prairies
The Texas Coastal Prairies extend westward along
the coast from the Sabine River, reaching inland 30 to 60
miles. Between the Sabine and Galveston Bay the line of
demarcation between the prairies and the Pine Belt for-
ests to the north is very distinct. The Coastal Prairie in
varying character extends along the Gulf from the Sa-
bine to the Lower Rio Grande Valley. The eastern half is
covered with a heavy growth of grass; the western half,
in a more arid area, is covered with short grass, and in

some places with small timber and brush. The soil is
heavy clay. Grass supports the densest cattle population
in Texas, and cattle ranching is the principal agricultu-
ral industry. Rice is a major crop, grown under irri-
gation from wells and rivers. Cotton, grain sorghum and
truck crops are grown.
Coastal Prairie areas have seen the greatest indus-
trial development in Texas history since World War II.
Chief concentration has been from Orange and Beau-
mont to Houston, and much of the development has been
in petrochemicals, or chemicals derived from petroleum.
Corpus Christi, and the surrounding Coastal Bend re-
gion, and, south of the coastal plains, Brownsville, with
its adjacent Lower Rio Grande Valley area, are rapidly
developing seaports, agricultural and industrial
sections. Cotton, grain, vegetables and citrus fruits are
the principal crops. Cattle production is significant, with
the famed King Ranch and other large ranches located
here.
Lower Rio Grande Valley
The deep alluvial soils and distinctive economy
cause the Lower Rio Grande Valley to be classified as a
subregion of the Gulf Coastal Plain. Here is concentrated
Texas' greatest citrus-winter vegetable area because of
the normal absence of freezing weather and the rich del-
ta soils of the Rio Grande. Despite occasional damaging
freezes, as in 1951 and 1961, the Lower Valley ranks high
among the nation's intensified fruit-and-truck regions.
Much of the acreage is irrigated from the Rio Grande,
although dryland farming also is practiced.
Rio Grande Plain
This may be roughly defined as lying south of San
Antonio and between the Rio Grande and the Gulf
Coast. The Rio Grande Plain shows characteristics of

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ENVIRONMENT