Over the past century, technology advances have had major impacts on mining practices and the nature of the mine and quarry sites in the United States. The evolution of current technologies, as well as the introduction of innovations, will continue and perhaps accelerate in the new century. Several industry objectives will drive future technology change, including lowering production costs, enhancing the productivity of workers and equipment, opening up new reserves and extending the life of existing ore bodies. Continuing to meet regulatory and stakeholder requirements in areas such as health and safety, environmental impacts, and land use. Between March and July 2000, the RAND Science and Technology Policy Institute conducted a series of in-depth, confidential discussions with key members of the mining community to elicit a wide range of views on technology trends in all sectors of the U.S. mining and quarrying industry. The discussions included 58 organizations engaged in coal, metals, aggregates, and industrial minerals production, as well as technology providers and research institutions. This report brings to light those technologies viewed by industry leaders as critical to the success of the industry currently, and critical technologies likely to be implemented between now and 2020.