The Dugway Sheep Incident, also known as the Skull Valley Sheep Kill, is a notorious event that took place in 1968. On March 13, the U.S. Army’s Dugway Proving Ground in Utah was testing nerve gas when, reportedly due to an accident, a jet sprayed VX, a potent nerve gas, over a large area off-course from its intended target.
This incident led to the death of approximately 6,000 sheep grazing in Skull Valley, an area located around 30 miles from the proving grounds. Symptoms such as convulsions suggested nerve gas poisoning, but the Army initially denied any connection with the deaths.
Eventually, after an investigation by local scientists, the government conceded that the sheep deaths were indeed caused by nerve gas exposure, but they insisted it was due to a wind shift that brought the gas to the valley rather than a direct spraying.
The incident led to a public outcry and increased scrutiny on the U.S. government’s handling and testing of chemical and biological weapons. This helped catalyze an anti-chemical weapons movement, which ultimately resulted in a ban on open-air chemical weapons testing in 1972. Despite the ban, the Dugway Sheep Incident has remained a significant part of the debate over chemical weapons and their potential environmental impact.
Documents relating to the event are archived below.
Central Intelligence Agency (CIA) Documents, Released October 4, 2017 [14 Pages, 2.1MB]