Founded in March 1913 by investor Charles R. Tips, the community was chartered on June 12, 1913, as Hamiltonburg, named for a local family. A town lot sale began on July 4, 1913. On May 1, 1914, the U.S. Postal Department renamed the townsite Three Rivers to mark the fork of the Nueces, Atascosa, and Frio rivers. Its present interests are ranching, farming, gas, oil, and recreation.