NULL Of 254 counties in the Lone Star State, Frio County is 50th in terms of its size (1,134 square miles). Frio County is in Edwards Plateau South Texas. The total value of about 1,000 acres of riverfront homes and property recently listed for sale in Texas's Frio County was almost $5 million. Browse all waterfront property for sale in Frio County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits! The most common type of land for sale by combined acreage in Frio County is undeveloped land.