YGNACIO CREEK. Ygnacio Creek rises four miles west of Freer in northeastern Duval County (at 27°52' N, 98°43' W) and runs northeast for twenty-three miles to its mouth on a former channel of the Nueces River, twenty-two miles southwest of Tilden in southwestern McMullen County (at 28°09' N, 98°43' W). It crosses low-rolling terrain and descends to flat terrain with locally shallow depressions. Clay and sandy loams support grasses, mesquite, and chaparral in the creek's upper reaches and water-tolerant hardwoods and grasses in its lower.