Los Brazos de Dios
The full name of the Brazos River is Los Brazos de Dios, “the arms of God,” as named by the Spanish explorers when they first came over. How and who exactly named it this is still a mystery but there are several popular legends surrounding the naming. The first is the exploration by Francisco Vasquez de Coronado and his men up the Llano Estacado. They were about to perish from lack of water when local Indians guided them to the river. The second is similar with a Spanish ship caught in the Gulf of Mexico with no drinking water left. The crew noticed a muddy streak in the waters and the ship followed it up to the mouth of the river. The third account stems from in the 1760s an extreme drought made it impossible for Spanish minors on the San Saba to work. To escape the drought, they headed toward the Waco Indian village where according to reports there was a never-ending stream. The fourth legend was told to Albert Pike in 1831. It accounts for the reversal of the names of the Colorado and the Brazos.
Information courtesy of the Handbook of Texas from the Texas State Historical Association.
The picture is a 1564 map of Nueva Hispania courtesy of the University of Texas at Arlington. The Brazos river is not clearly marked on this map. It is very difficult to find a map with the river on it before the 1800s.