Trans-Pecos, Texas: Region, Not a Mountain Range

Trans-Pecos is a geographic region, not a mountain range. It comprises the 27 westernmost counties of Texas, west of the Pecos River.

Geography

• Border: Mexico (south), New Mexico (west).
• Landscape: Basin and Range province — desert basins (Chihuahuan Desert) interrupted by fault-block mountain ranges (Davis, Guadalupe, Chisos, Franklin, Chinati Mountains).
• Highest Point: Guadalupe Peak (8,751 ft) — highest in Texas.
• Climate: Arid/semi-arid; dramatic diurnal temperature swings.

Key Features

• Big Bend National Park
• Guadalupe Mountains National Park
• Marfa (art, mystery lights)
• El Paso (major city, eastern edge)
• McDonald Observatory (Mt. Locke)

Trans-Pecos is Texas's "mountain and desert country"—a region defined by its distinctive topography, not a single range.