Interior Lowlands region map
One of the 4 natural regions · North Central Plains · about 750 to 2,500 ft · Central Time
The Interior Lowlands, taught in Texas schools as the North Central Plains, is the middle ground: lower than the plains to the west, drier than the prairies to the east. It is the Texas end of the same Central Lowland that runs up through Oklahoma and Kansas, and it stops abruptly at the wall of the Caprock Escarpment.
From the Red River south to the Colorado, and from Fort Worth west to the foot of the Caprock near Post and Matador.
Where it starts and ends
The eastern boundary is the Eastern Cross Timbers and, further south, the Balcones fault line. On the ground this is the change from black prairie clay to limestone and sand — Fort Worth stands on the Fort Worth Prairie on the west side of it, Dallas on the Blackland Prairie of the Gulf Coastal Plains 30 miles east. The old line about Fort Worth being "where the West begins" is a statement about geology as much as culture.
The western boundary is unmistakable: the Caprock Escarpment, a 200 to 1,000 foot rise that runs from the Canadian River south through Briscoe, Floyd, Motley, Dickens, Crosby and Garza counties. Above it is the flat, treeless Llano Estacado of the Great Plains; below it is broken red country. The northern boundary is the Red River and Oklahoma; the southern edge is roughly the Colorado River near Brownwood, where the land begins climbing onto the Edwards Plateau.
The three sub-regions
| Sub-region | Ground and soil | Rain | Land use |
|---|---|---|---|
| Grand Prairie | Cretaceous limestone with thin, stony calcareous soils; almost no trees on the open prairie | 26–34 in | Cattle, hay, small grain; the Fort Worth end is now suburb |
| West Cross Timbers | Deep sandy soils over sandstone, carrying post oak and blackjack oak | 26–32 in | Peanuts, watermelons, dairies, pecans, cattle |
| Rolling Plains | Permian red beds — reddish-brown clay loams cut by mesquite flats and gypsum breaks | 20–28 in | Cotton, winter wheat, stocker cattle, oil, wind |
The red water of the Red River comes from these Permian beds, and so does the color of the badlands at Copper Breaks in Hardeman County. Salt and gypsum in the same beds make several Rolling Plains streams too briny to drink.
Counties in the region
| Sub-region | Counties |
|---|---|
| Grand Prairie and the Lampasas Cut Plain | Tarrant, Johnson, Somervell, Bosque, Hamilton, Coryell, Lampasas, Mills, Cooke |
| West Cross Timbers | Wise, Parker, Hood, Erath, Palo Pinto, Jack, Montague, Eastland, Comanche, Brown, Stephens |
| Rolling Plains (north) | Wichita, Wilbarger, Hardeman, Foard, Knox, Baylor, Archer, Clay, Young, Throckmorton, Childress, Cottle, King, Hall |
| Rolling Plains (south) | Haskell, Stonewall, Kent, Fisher, Jones, Shackelford, Callahan, Taylor, Nolan, Mitchell, Scurry, Coleman, Runnels |
Counties along the caprock — Briscoe, Floyd, Motley, Dickens, Crosby, Garza, Borden — are split down the middle, with High Plains in the west half and Rolling Plains in the east.
Cities
- Fort Worth
918,915 people (2020), the largest city in the region and the fifth-largest in Texas, on the bluffs above the Trinity at the eastern edge of the Grand Prairie.
- Abilene
125,182 people, on I-20 in Taylor County, with Dyess Air Force Base and three universities.
- Wichita Falls
102,316 people on the Wichita River near the Red River, at the crossing of US-287, US-281 and US-82.
- Arlington
394,266 people. The city sits on the Eastern Cross Timbers, the belt of sandy oak woodland that marks the boundary with the Coastal Plains.
- Nolan County
Sweetwater, on I-20, sits in the middle of one of the densest concentrations of wind turbines in the United States.
- Erath County
Stephenville, on US-377 and US-281, is the center of the state's dairy country on the sandy Cross Timbers soils.
- Palo Pinto County
Possum Kingdom Lake fills the Brazos River canyon here, reached by US-180 west of Mineral Wells.
- Wichita County
Burkburnett, on the Red River north of Wichita Falls, gave its name to the 1918 oil boom that made the city.
Roads
- I-20 – the main east–west route, running from Fort Worth through Weatherford, Ranger, Abilene and Sweetwater toward Midland.
- US-287 – the northwest diagonal from Fort Worth through Decatur, Bowie and Wichita Falls to Childress and Amarillo.
- US-281 and US-183 – the north–south pair through Jacksboro, Seymour and the Rolling Plains counties.
- US-83 – the western spine: Abilene, Haskell, Vernon and on into Oklahoma.
- US-82 – Wichita Falls east to Gainesville and Sherman, west to Lubbock up the caprock at Dickens.
- US-180 – Fort Worth through Mineral Wells and Breckenridge to Albany and Anson.
- US-84 – the diagonal from Waco through Gorman and Snyder toward Lubbock.
Wheat, peanuts, oil and wind
Farming here follows the soil. The sandy Cross Timbers counties — Comanche, Erath, Eastland — grow peanuts, pecans and forage for a heavy concentration of dairies around Stephenville and Dublin. The Rolling Plains counties west of a line through Vernon and Haskell grow dryland cotton and winter wheat, with wheat pasture used to graze stocker cattle through the winter. The Grand Prairie's thin limestone soil never made good cropland, so it stayed in grass and became the ranch country that supplied Fort Worth's stockyards.
Three oil booms shaped the region: Electra in 1911, Ranger in Eastland County in 1917, and Burkburnett in Wichita County in 1918. A century later the same ground produced the Barnett Shale, the play under Tarrant, Johnson, Wise and Denton counties where hydraulic fracturing of shale gas was first made to pay in the 1990s. Since then the open, windy Rolling Plains have filled with turbines, thickest along I-20 in Nolan, Taylor and Scurry counties.
Distinctive facts
| Eastern boundary | The Eastern Cross Timbers; Fort Worth is in this region, Dallas is not |
| Western boundary | The Caprock Escarpment, a rise of 200–1,000 ft into the Llano Estacado |
| Largest city | Fort Worth, 918,915 (2020) |
| Second-smallest county population in Texas | King, 263 people in 913 sq mi |
| Biggest lake | Possum Kingdom on the Brazos, in Palo Pinto County |
| Shale gas | The Barnett Shale, drilled from under the Fort Worth suburbs |