The Missouri Resource Assessment Partnership (MoRAP) began the first statewide Aquatic Gap Pilot Project in 1997.  As part of this project a number of datasets were developed to facilitate conducting an aquatic gap analysis.  The datasets include a hierarchical classification of riverine ecosystems, predicted species distribution maps, riverine stewardship characterizations, and indices of human threats.  Since this time, several improvements have been made to the methodologies developed and used in Missouri.  For instance, the aquatic species models subsequently developed for Nebraska have gone beyond the more simple presence/absence models based on local variables that were developed for Missouri.  These newer models provide occurrence probabilities for each stream segment in the 1:100,000 National Hydrography Dataset and incorporate both watershed and local predictor variables.  In addition, a new project funded by the Environmental Protection Agency (EPA) and the Missouri Department of Natural Resources is underway that expands upon methods and data layers developed for Aquatic GAP to assess threats to aquatic ecosystems at a much finer resolution across EPA Region 7.  This presentation will describe these advances in modeling aquatic species and assessing human threats to aquatic ecosystems.  These refinements illustrate how GAP datasets are evolving to better meet the needs of natural resource professionals, legislators, and the public and, in addition, how GAP information is being used by state and federal resource agencies for their various management, regulatory, and outreach programs.