Two Thousand Six Hundred Tons in Concrete Bunkers

From nineteen fifty-two until two thousand twenty-three, the United States Army stored chemical weapons on the eastern plains near Pueblo. The stockpile consisted of approximately two thousand six hundred tons of mustard agent, a blister agent used in the First World War, loaded into one hundred fifty-five millimeter artillery shells. The shells sat in concrete bunkers. The facility was called the Pueblo Chemical Depot.

Pueblo residents knew the depot was there. It appeared on maps. There was limited but real public discussion of it over the decades. But it was not a central fact of Pueblo's civic identity in the way that the steel mill was, or the flood of nineteen twenty-one, or the labor wars. It was present and largely unnarrated.

The United States signed the Chemical Weapons Convention in nineteen ninety-three, committing to destroy its chemical weapons stockpile. The Pueblo depot was one of the last American storage sites to complete destruction. The technology used was hydrolysis, a chemical neutralization process that broke down the mustard agent without incineration. The destruction program took years longer than originally planned, partly due to technical challenges and partly due to community concerns about incineration alternatives. It was declared complete in two thousand twenty-three.

The specific health effects on residents who lived near the depot for decades are a subject where the public record is less complete than historians would want. The existing documentation from Colorado Public Radio and the Colorado Sun covers the depot's existence and destruction timeline. A fuller account of how proximity to that stockpile affected Pueblo's population over seventy years is not yet established in accessible sources.

The bunkers are empty now. The eastern plains look the same as they did before.