Reducing greenhouse gas emissions by injecting unwanted gases into unused deep-brine-bearing aquifers is an attractive option because large-volume sinks underlie many carbon dioxide sources. In this study, funded by DOE/NETL, we inventoried the 16 geologic characteristics of 21 brine-bearing formations in the continental United States to provide basic data needed to assess the feasibility, costs, and risks of this sequestration method. We investigated a diverse spectrum of target formations and compiled a GIS database by digitizing published and unpublished data from each basin.