The purpose of this investigation has been to determine the characteristics of the seismic disturbances which occurred near Mount San Gorgonio, San Bernardino County, California on October 22, October 24, and intermittently thereafter until October 31. The principal shock occurred at 6:47:56.1 Pacific Standard Time on October 24, 1935. Travel-times for several phases have been determined, and the thickness of layers have been determined, and the thicknesses of layers for Southern California have been calculated