Enchanted Rock is a spectacular granite pluton just west of State Highway 965 near the Gillespie-Llano county line in southern Llano County (at 30°30'N, 98°48' W). The granite dome rises some 385 feet above the streambed of nearby Sandy Creek to a maximum elevation of 1,825 feet above mean sea level. This great monadnock is the largest pink granite monadnick in the United States. It is part of a rough, segmented ridge, which is in turn part of the surface expression of a large igneous batholith of middle Precambrian material intrusive into earlier metamorphic schists and gneiss. This intrusive granite was exposed after later sedimentary rock deposition and extensive erosion. In 1992 a University of Texas geophysics researcher, Ian W. D. Dalziel, linked Enchanted Rock geologically with granite peaks in Antarctica. The name Enchanted Rock derives from Spanish and Anglo-Texas interpretations of Indian legends and related folklore, which attribute magical and spiritual properties to the ancient landmark. According to one nineteenth-century writer, "the Indians had a great awe amounting almost to a reverence" for the rock (see ENCHANTED ROCK LEGENDS).
The first European to see Enchanted Rock was possibly Álvar Núñez Cabeza de Vaca, who traveled through this area before 1536. The rock was visited and described by many during the sixteenth, seventeenth, and eighteenth centuries. Capt. Henry S. Brown, who came from Green DeWitt's colony on a punitive Indian expedition in 1829, appears to have been the first Anglo-Texan to visit the location. William B. DeWees described the rock in 1834. Other writers describe an Indian encounter of Captain John (Jack) Coffee Hays at Enchanted Rock. The rock has also been the subject of paintings by such artists as Hermann Lungkwitz. Enchanted Rock was the subject of a natural-area survey published by the Lyndon Baines Johnson School of Public Affairs in 1979. The site was acquired by the Texas Parks and Wildlife Department in that year and was opened as Enchanted Rock State Park (see ENCHANTED ROCK STATE NATURAL AREA) in March of 1984.