Where can I find distribution maps for plants that grow in Wyoming?

Go to the website of the Rocky Mountain Herbarium.  Then click on RM Specimen Database. There, maps can be produced that show the approximate, documented distribution of all plant species known to occur in Wyoming. The Latin name (at least the genus) of the plant must be known and can often be found by a web search using the common name.

Also at this site, lists of plants expected to occur in specific areas can be produced, which is an excellent tool for obtaining a preliminary list of the plants likely to be found in the area of interest (such as a ranch, state park, or study area).

Wyoming launches a new natural resource mapping website

Developed in collaboration with the Wyoming Geographic Information Science Center, this website provides maps that are useful for natural resource managers.  Maps include, for example, the locations of sage grouse conservation areas, wetland bird migration hotspots, and areas with wind turbines, oil wells, and transmission lines.  Users can access this new mapping tool for free at and can overlay different data sets on a map of Wyoming. 
What is the best land cover map for Wyoming and the region?

This depends on the use to be made of the map, but several options for land cover are provided by the Wyoming Geographic Information Sciences Center (WyGISC).  At this website, type "land cover" or "landcover" into the "Find Data" window.  A list of downloadable data sets will appear.  In the same way, maps of geologic history, coal mines, and other features can be accessed.  Special software may be required for some maps.

The map below is fig. 1.5 in Mountains and Plains: The Ecology of Wyoming Landscapes (2nd edition, Yale University Press). This small map shows the distribution of 11 vegetation types in Wyoming and adjacent parts of neighboring states, plus large areas of water, cultivation, and urban/industrial developments. The book includes an explanation of the legend.  A more detailed land cover map is available from WyGISC.