YO-LO-DIGO CREEK. Yo-Lo-Digo Creek, also known as Big Yo-lo-Digo Creek, rises ten miles northwest of Batesville in far northwestern Zavala County (at 29°00' N, 99°28' W) and runs southeast for sixteen miles to its mouth on the Leona River, three miles east of the county line and eighteen miles west of Pearsall in far west central Frio County (at 28°51' N, 99°22' W). Goat Hollow Creek joins Yo-Lo-Digo Creek immediately before its mouth. Little Yo-lo-Digo Creek rises three miles west of the Zavala-Frio county line (at 28°58' N, 99°28' W) and runs southeast twelve miles to its mouth on Yo-lo-Digo Creek, two miles east of the county line (at 28°51' N, 99°23' W). The surrounding rolling and flat terrain is marked by some steep margins and surfaced by caliche and occasional siliceous sand and gravel that support oak, juniper, mesquite, and grasses interspersed with pecan and willow. The creek is supposed to have been named on a dark night when Mexicans walking toward it single file heard the leader make a noise that sounded like a splash. One behind called, "Es agua?" ("Is it water?"), and the leader replied, "Yo lo digo" ("I say it [is]"). According to another local tradition the creek was named after an incident in which a Mexican soldier who, after receiving no warning by fellow sentinels of an enemy attack, gave the warning himself; when asked who had given the warning, he replied, "Yo lo digo."
Mrs. W. A. Roberts, "Frio County Has a Colorful History," Frontier Times, June 1936.