Selecting suitable land for a vineyard is important for sustainable grape production. This project used two approaches to using GIS to identify areas that are suitable for wine grape growth in Washington county, southern Utah based on criteria from several sources (e.g., experts' knowledge, literature review). Several different GIS layers were used in this study including Digital Elevation Model, Soil Type, Land Ownership, Vegetation (DVNI), and climatic variables. The first method used overlay analysis to create a binary suitability map, while the second method used fuzzy logic to create a suitability map which ranges from 0 to 1, where 0 represents non-suitable and 1 represents most suitable. The maps were evaluated by comparing the location of current vineyard sites with the suitability map, and the results revealed that less than 10% of the suitable areas were already used for vineyards.