Duval County is in Rio Grande Plains Texas. Of the 254 counties in the Lone Star State, 1,795-square-mile Duval County ranks 14th by size. Recent listings of residential land for sale in Duval County, Texas, totals 1,000 acres and a combined market value of approximately $6 million. The most common type of land for sale by combined acreage in Duval County is hunting land. The average price of residential land for sale in Duval County was $346,394. Browse all residential land and rural property for sale in Texas to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.