For the past three years the Atomic Energy Commission and its contractors have been considering the practicability of carrying out large-scale excavation projects using nuclear explosives. Results of past experience with both nuclear and chemical explosives have been evaluated and a series of high explosive experiments have been executed. In addition, a series of small explosions will be fired in basalt to obtain cratering data for a competent medium. The Soviet Union has been using massive charges of chemical explosives for excavation purposes for several years and is expanding its activities. In the paper the present status of all of these experiments is described and the future program outlined, including the proposed nuclear excavation experiment at Cape Thompson.