Los Almagres Mine
LOS ALMAGRES MINE. An expedition seeking a site for an Apache mission in 1753 led to the discovery of Los Almagres Mine in what is now Llano County. Traversing the Central Mineral Region, Lt. Juan Galván heard from Indians of a cerro de almagre, a hill of red ocher, indicating the presence of mineral-bearing ores. Upon Galván's return to San Antonio, several men from that settlement were guided to the hill by Apache Indians in August 1753. No valuable ore was found, but interest in the hill containing gossan refused to die. Governor Jacinto de Barrios y Jáuregui, fearful that the use of Apache guides by unauthorized prospectors would arouse the Comanches, decided to send an official expedition. To lead it, he chose Bernardo de Miranda y Flores, who left San Antonio with twenty-three soldiers and citizens on February 17, 1756.
Full article on the Texas State Historical Association's Handbook of Texas Online