The State of Colorado seems to have significant geothermal energy potential. Indeed, several successful geothermal facilities are located in the state already. A prior study showed that about 500 megawatts of electricity could be produced in Colorado with geothermal energy and that about 30 communities could use geothermal for their direct thermal energy needs (Coe, 1978). A more specific indication of the potential is necessary, however, for several reasons. First, tax dollars are allocated by the Federal government to aid the research and development of various energy forms, including geothermal energy. The extent to which the expenditure of public funds is justified depends upon the extent of the probable return of benefits to the public. In the case of geothermal energy, these benefits come in the form of energy on line at an affordable price and without intolerable negative impacts. Secondly, the Congressional mandate that led to this planning effort requires the encouragement of the commercial development of geothermal energy (P.L. 93-410, Sec. 2). It is hoped that providing ideas and information about the geothermal energy potential may help stimulate local communities, users, and developers to develop and use a valuable, but so-far virtually-untapped resource. As such, the Colorado Geological Survey, under a contract from Four Corners and the Department of Energy, is evaluating the potential for developing the geothermal resources of Colorado. This report details that potential. Finally, the study describes constraints that are limiting geothermal energy development. Recommendations may then be made for measures designed to overcome those constraints.