The Iowa Gap Analysis Project (IA GAP) began in 1997 to identify areas in the state where vertebrate species richness lacked adequate protection under existing land ownership and management regimes. To accomplish this goal, the IA GAP team prepared an assortment of datasets that led to three main pieces of information: Iowa vegetation types; Iowa vertebrate/habitat relationship models for 288 species; Iowa land stewardship (ownership and management). When the project began, there were few stat ewide datasets available that provided the type of data needed for this project. Conse quently, much effort was devoted to building the previously mentioned key da ta layers at a sufficiently fine scale and resolution for subsequent analysis. At the completion of the project, these data became freely available, with the intent that they will be used by those responsible for managing the state’s valuable natural resources, and by the public, so that every one can be better informed. With this in mind, we emphasize that these data are dynamic, and in some places, already out-of date. Nonetheless, the data and analyses that constitute IA GAP represent an important first step toward understanding the st atus of vertebrates and land cover in Iowa and planning for the conser vation of their biodiversity