Recent efforts to site renewable energy projects have provoked as much, if not more,opposition than conventional energy projects. Because renewable energy resources are oftenlocated in sensitive and isolated environments, such as pristine mountain ranges or coastalwaters, siting these facilities is especially difficult. Moreover, the viability of different renewableenergy projects depends not only on complex economic and environmental factors, but also onthe availability of supporting infrastructures, such as transmission lines. This paper examines thespatial relationships between four types of renewable energy resources – wind, solar, geothermal,and biomass – and an empirical measure of state-level transmission-line siting difficulty.Analyses explore the locations of renewable resource potential relative to areas of high sitingdifficulty, state electricity demand and imports, and states with renewable portfolio standards(RPSs). Major results reveal that state resource potential varies, and siting is significantly moredifficult in states that import electricity and those with RPSs. These results suggest that stateswith the greatest incentives to develop renewable energy also face the most serious obstacles tositing new facilities.