The GIS Map Viewer will allow you to find properties within the County of Napa by Parcel or Address, view property data such as permits, save property image to JPG or PDF. Use this link to quickly and efficiently research property data. GIS Public Map Viewer
This Map Viewer requires that Microsoft install a plugin on your internet browser called 'Silver LIght". This softwares allows you to use the Map Viewer and is harmless to your computer.