Ground-penetrating radar and resistivity measurements were made on 20-31 March 1977 in support of limited exploration and excavation of Victorio Peak, White Sands Missile Range, New Mexico, by Expeditions Unlimited. The Survey by SRI International (formerly Stanford Research Institute) confirms the existence of large caverns beneath the mountains as well as tunnels, fissures, and other features of geophysical interest, pertinent to the legends that a treasure cache was discovered within the peak in 1937. The uniqueness of the radar work reported is a result of lower-than-average radio-frequency attenuation in the peak permitting sounding to depths as great as 400 ft.