Concerns over fluctuating oil prices and declining petroleum production worldwide have revived interest in oil shale as a potential resource. The Energy Policy Act of 2005 (P.L. 109-58) identified oil shale as a strategically important domestic resource and directed the Department of the Interior to promote commercial development. Oil shale development would require significant amounts of water, however, and water supply in the Colorado River Basin, where several oil shale reserves are located, is limited. This report will provide a brief overview of water rights in Colorado, Utah, and Wyoming, including changes that may be made to currently held water rights and the possibility for abandonment of unused water rights.