INTRODUCTION This data release contains mineral resource data for metallic and nonmetallic mineral sites in the State of Wyoming. Along with resource data is additional data, such as mineralized areas and mining districts; mine, prospect and commodity information; claim density by section; county boundaries; quadrangles; and simplified geology. All the data are provided in both spreadsheet format (Microsoft Excel) and in formats for two commonly used Geographic Information Systems (GIS) software packages (MapInfo and ESRI's ArcView). Not only does GIS software allow the data to be shown as layers in "map" views that can be displayed with various geographic and geologic data, but the data can be queried and analyzed relative to data in any of the layers. Free shareware, ArcExplorer, is provided with this report so users may display the data in "map" views and query the various datasets (Appendix A) without requiring a GIS program such as Arc/Info, ArcView, or MapInfo. Explanatory material is in the Introduction (and root directory on the CD). Part A includes all the data files with subdirectories for ArcView and MapInfo. Part B contains illustrations as .pdf maps (an installation file for Adobe Acrobat Reader for viewing the .pdf files is on the CD). Part C contains metadata, explanatory details on the structure and content of each data file. TO BEGIN 1. If a program to read .pdf files is not already installed on the computer, install Adobe Acrobat Reader (navigate to PartB and run ar505enu.exe). 2. Read WY_text.pdf and print out pages i-iv for reference. (Reading .pdf files requires Adobe Acrobat Reader) 3. Install ArcExplorer (run ae2setup.exe). 4. Open ArcExplorer and open either existing project file (WY_geol.aep or WY_mines.aep) 5. To use the data with MapInfo or ArcView, open the desired program and navigate to the corresponding subdirectory in Part A. Open the Workspace (for MapInfo, .wor) or Project (for ArcView, .apr) files. If the Workspace or Project does not open completely, the path names in the .wor or .apr file can be adjusted using any text editor. 6. To use the data with any other GIS program, follow that program's instructions for importing MapInfo or ArcView files.