A facility was designed and subsequently has been built for the utilization of californium-252 in research on moisture, density, and other properties of soil and rock in relation to their engineering characteristics. Preliminary testing shows good correlations between neutron radiation and the quantification and distribution of moisture both in soil slices and steel-encased undisturbed soil samples. Such data, when used in conjunction with X-ray studies, are valuable in furthering the knowledge and understanding of soil and rock behavior. Continued research will refine techniques for more detailed study of properties of earth materials. Detailed plans of the facility and its components are given in Appendix A.