EAST FRIO RIVER. The East Frio River, a spring-fed stream that is intermittent for much of its course, rises in southwestern Kerr County just north of the intersection of the Real, Kerr, and Bandera county lines (at 29°56' N, 99°36' W) and descends into the Frio canyon, winding southwest over a bed of limestone, gravel, and calcareous soil for more than twenty-two miles to its mouth on the West Frio River, just northeast of Leakey in Real County (at 29°44' N, 99°45' W). The surroundings are characteristic of the heavily dissected canyonlands of the Balcones Escarpment on the southern edge of the Edwards Plateau, forested with open stands of live oak, mesquite, and Ashe juniper. In Real County U.S. Highway 83 closely follows the eastern bank of this stream.