Terlingua Mercury: The Poison Mine Nobody Cleaned Up

Cinnabar is a bright red ore, the color of fresh rust, and it contains mercury. In the eighteen eighties, prospectors found it in the limestone formations of the Terlingua district in far southwest Texas, and the Chisos Mining Company began extracting it on an industrial scale. By the time the first World War created an enormous demand for mercury, which was essential to the detonators and fuses in munitions and artillery shells, Terlingua had become the single largest mercury-producing operation in the United States.

The workers who processed the ore were primarily Mexican and Mexican American men. The process involved loading cinnabar into enclosed retort furnaces and heating the ore until the mercury vaporized, then condensing it back into liquid form. The men worked in these enclosures in the desert heat, breathing mercury vapor through a full shift, day after day, for years.

Mercury vapor at sustained exposure levels produces tremors, cognitive impairment, and damage to the kidneys and nervous system. Community oral histories from Terlingua describe symptoms consistent with serious occupational mercury poisoning among survivors of the mining era. But the health records of the workforce do not survive in any accessible archive. The total burden of illness and death from the Terlingua mercury years is not established in the public record. No individual names appear in the documented account of what happened to those workers.

The Chisos Mining Company collapsed in the early nineteen forties. Terlingua became a ghost town, then an artists' community, then famous for a chili cook-off held every November. The collapsed retort furnaces are still there, open to the sky. The arsenic and mercury compounds that leached into the soil are also still there.