A major tributary is Brady Creek, which is 90 miles long and parallels the path of the San Saba to the north.
[1] The river was named by the governor of Spanish Texas, Juan Antonio Bustillo y Ceballos, in 1732.
He called it Río de San Sabá de las Nueces ("River of Saint Sabbas of the Walnuts"), because he and his troops had arrived December 5, the feast day of St. Sabbas (439–532), a major figure of early Christian monastic life.
Santa Cruz de San Sabá Mission was established on the river in 1757.
As of 2013[update], the San Saba River was an overappropriated stream with large stretches of the river dry, depriving downstream riparian users of water, while upstream flow was being diminished by pumping of aquifers hydrologically connected to the stream.