Under the U.S.-USSR Joint Agreement on Cooperation in the Field of Environmental Protection of May 1972, a program entitled Earthquake Prediction was begun. During 1973, working groups were organized on each side, with M.A. Sadovskiy of the Soviet Academy of Sciences, Institute of Physics of the Earth, and R.E. Wallace, U.S. Geological Survey, as cochairmen. A plan for cooperative working projects was developed, and the first exchanges took place in 1974.