Though the salt marsh harvest mouse (Reithrodontomys raviventris; SMHM) has been listed as state and federally endangered since the early 1970’s, there has never existed a comprehensive, central repository for survey data. Further, survey methods differ among monitoring entities, and for many older efforts raw data was not retained and only a minimal summary of the methods and results now exists. This lack of an all-inclusive data set has prohibited researchers from performing any large-scale assessments of correlations between SMHM densities, and habitat features and environmental conditions. Localized analyses often contradict one another, and likely provide a misleading picture of SMHM ecology. These deficiencies have had consequences for planning and executing recovery actions such as tidal restoration. Over the past two years myself and my collaborators have compiled the most comprehensive database of SMHM survey data and created a GIS of environmental variables that are likely to impact SMHM populations. Using these tools I performed the first range-wide spatial analysis of the relationship between SMHM occupancy and densities, and environmental variables. The resulting heat maps of SMHM hot spots, high quality but unoccupied patches, and low quality patches will support the effective application of recovery actions.