March 17, 1968
Six thousand sheep are killed during the Dugway sheep incident, also known as the Skull Valley sheep kill
The affected sheep were from ranches near a U.S. Army base in Utah, which some believe accidentally or purposefully released either nerve gas or another agent of biological or chemical warfare. A few days before the sheep’s deaths were reported, 3 separate nerve gas experiments were conducted: a nerve gas artillery shell was fired, 160 gallons of nerve agent was burned in an open pit, and an aircraft sprayed nerve agent on a target. Strangely, though the sheep exhibited nerve agent side effects, no other animals “including cows, horses, dogs, rabbits, or birds,” seemed to suffer from the same effects.