ECOREGIONS OF TEXAS - The Balcones Escarpment Part 1
The Balcones Escarpment is an interesting geological feature which starts near Del Rio, runs eastward to San Antonio, and then northeastward up the IH 35 corridor all the way to Georgetown. Interstate 35 runs just east of the fault line and follows the length of the Texas Blackland Prairie region. When driving between San Antonio and Dallas on IH 35, you will see (almost exclusively) Blackland Prairie (this excludes IH 35W to Fort Worth because it enters the crosstimbers and grand prairie regions). The prairie is easy to recognize with small hackberry trees which grow along fence lines, rich black soil, fields, and wild sunflowers which grow everywhere. Other towns within the Blackland Prairie are Waco, Temple, Belton, Taylor, Seguin, Lockhart, Plano, Dallas, Frisco, Hillsboro, Corsicana, Rockwall, Marlin, Mexia, and many others. Dallas, Rockwall, and Collin Counties are the only three Texas counties which lie completely within the Texas Blackland Prairies. (Eco-Region 32 according to EPA maps) .
Cities which strattle the Balcones Escarpment are Del Rio, San Antonio, New Braunfels, San Marcos, Austin, Round Rock, and Georgetown.
Towns which lie within the Balcones Canyonlands region are Blanco, Wimberly, Dripping Springs, Spring Branch, Boerne, Kerrville, Comfort, Kendalia, Waring, Sisterdale, Bandera, Medina, Leakey, Utopia, Concan, Bulverde, Grey Forest, Leander, Lakeway, and Bee Cave.
Personally, I believe the most scenic Hill Country drive is Ranch Road 337 between Medina and Leakey, just a short drive NW of San Antonio.
EPA ECOREGIONS:
Level I - Great Plains (9);
Level II - South Central Semiarid Prairies (9.4);
Level III - Texas Blackland Prairies (32) MEETS the Edwards Plateau (30);
Level IV - Northern Blackland Prairie (32a) MEETS the Balcones Canyonlands (30c).