It is the most mountainous and arid portion of the state, and most of its vast area (outside the city of El Paso) is sparsely populated.

The area is known for the natural environment of the Big Bend and the gorge of the Rio Grande, part of which has been designated a National Wild and Scenic Rivers System.

The Trans-Pecos region consists of nine counties: Brewster, Culberson, El Paso, Hudspeth, Jeff Davis, Pecos, Presidio, Reeves, and Terrell.

[3] Jeff Davis is the most Republican county in the region, last being won for the Democratic Party by Jimmy Carter in 1976,[3] although even George W. Bush’s 66.79 percent of the vote in 2000[4] stands modest compared to the 90 percent or more Republican vote common in Panhandle counties since the turn of the millennium.

Hudspeth, Pecos and Terrell Counties, last won for the Democrats by Bill Clinton in 1996,[3] have become comparably Republican to Jeff Davis in the past couple of elections.

The remainder of the region is located entirely within Texas's 23rd congressional district, currently represented by Congressman Tony Gonzales (R-San Antonio).