Below this spot, experiments in the Vela Uniform Program sponsored jointly by the Department of Defense and the Atomic Energy Commission were conducted in salt at depths of 2700 and 2715 feet. A 33-kiloton nuclear device was detonated on October 22, 1964, as the Salmon Event, the first of the Dribble series, to evaluate the decoupling principle and study seismic wave propagation in the southeast United States. A 380-ton nuclear device was detonated on December 3, 1964, as the Sterling Event to determine the extent of decoupling of a cavity in salt and the accuracy of decoupling calculations. The Miracle Play series consisted of two gas explosions conducted in the cavity on February 3, 1969, and April 19, 1970, to determine the decoupling effect of explosions in an open cavity and the reduction in decoupling caused by overdriving a cavity. No excavation, drilling, or removal of materials is permitted without U.S. Government permission to penetrate the subsurface below the 1470-acre tract within Sections 11, 12, 13, and 14, T2N, R16W, Saint Stephens Meridian, Mississippi.