Mercury, or quicksilver, comes from the red ore cinnabar, which Native Americans used as a durable pigment and which appears in ancient drawings in many places in Big Bend. Cinnabar was discovered in the Terlingua area in the early 1890s, and by 1900 four enterprises had recovered and refined more than 75,000 pounds of mercury. The Chisos Mining Company was incorporated in 1903 and by 1918 had become the largest single producer of mercury in the US. Mercury was extracted by heating crushed ore to about 360 degrees until the metal was released as a dense vapor, then condensing the vapor and recovering the pure liquid in metal flasks. Fuel for the furnaces was a constant problem because timber for many miles was quickly exhausted, so miners used nearby low-grade coal deposits to produce a flammable gas containing methane. Transportation was extremely difficult: processed metal was hauled 100 miles to the nearest railroad in heavy freight wagons drawn by teams of 8-12 mules, and machinery and equipment for the mines, including pieces weighing as much as 18,000 pounds, were brought in the same way over trips that sometimes took weeks through rugged terrain. Although the first commercial use of an automobile in Brewster County took place in 1917, wagons and mules remained the main means of heavy transport until the early 1930s. Mercury had many uses, but a primary market was the manufacture of explosives, and the fortunes of the Terlingua Quicksilver District rose and fell with periods of large-scale warfare, especially from 1912-1921 and 1936-1944, when interruptions in European supplies, especially from Spain, made the Terlingua deposits economically and strategically valuable. The Chisos Mining Company went bankrupt in 1942, operations ended permanently in 1944, and most structures and equipment were later dismantled and sold as salvage. The site was largely unused until 1967, when the world’s first Chili Cook Off was held in Terlingua Ghost Town, and the International Chili Championship is still held nearby on the first Saturday of each November. The mercury deposits formed over immense spans of geologic time as limestones and clays were laid down in a shallow sea, tectonic collision warped and fractured the bedrock, rising magma and volcanic activity drove superheated acidic mineral waters and gases through the limestone, and cooling left deposits of mercury along with other minerals before Basin and Range fault-block mountains developed.