South Texas is typically classified as the area between the San Antonio metro area and south to the Rio Grande and Gulf of Mexico. Land for sale in McMullen County, Texas, recently totaled around $19 million and approximately 5,000 acres. McMullen County ranks 237th out of 254 counties in the Lone Star State for the combined amount of land currently advertised for sale. Of all land and rural real estate for sale in McMullen County, Tilden featured the most land for sale. Economically speaking, McMullen County's is largely dependent on mining and mineral extraction-related businesses and services. McMullen County is Texas's 46th largest county (1,156 square miles). It's located in the Rio Grande Plains Texas region of the state.